Sergi Papiol

Schizophrenia and bipolar disorder are two distinct diagnoses that share symptomology. Understanding the genetic factors contributing to the shared and disorder-specific symptoms will be crucial for improving diagnosis and treatment. In genetic data consisting of 53,555 cases (20,129 bipolar disorder [BD], 33,426 schizophrenia [SCZ]) and 54,065 controls, we identified 114 genome-wide significant loci implicating synaptic and neuronal pathways shared between disorders. Comparing SCZ to BD (23,585 SCZ, 15,270 BD) identified four genomic regions including one with disorder-independent causal variants and potassium ion response genes as contributing to differences in biology between the disorders. Polygenic risk score (PRS) analyses identified several significant correlations within case-only phenotypes including SCZ PRS with psychotic features and age of onset in BD. For the first time, we discover specific loci that distinguish between BD and SCZ and identify polygenic components underlying multiple symptom dimensions. These results point to the utility of genetics to inform symptomology and potential treatment.

Observational studies have suggested that psychometric psychosis liability and a functional polymorphism in the catechol-O-methyltransferase (COMT Val(158)Met) gene moderate the psychosis-inducing effect of cannabis. To replicate and extend this finding, a double-blind, placebo-controlled cross-over design was used in which patients with a psychotic disorder (n=30), relatives of patients with a psychotic disorder (n=12), and healthy controls (n=32) were exposed to Delta-9-tetrahydrocannabinol (Delta-9-THC, the principal component of cannabis) or placebo, followed by cognitive assessment and assessment of current psychotic experiences. Previous expression of psychometric psychosis liability was also assessed. Models of current psychotic experiences and cognition were examined with multilevel random regression analyses to assess (i) main effects of genotype and condition, (ii) interactions between condition and genotype, and (iii) three-way interactions between condition, genotype, and psychometric psychosis liability. Carriers of the Val allele were most sensitive to Delta-9-THC-induced psychotic experiences, but this was conditional on prior evidence of psychometric psychosis liability. Delta-9-THC impacted negatively on cognitive measures. Carriers of the Val allele were also more sensitive to Delta-9-THC-induced memory and attention impairments compared to carriers of the Met allele. Experimental effects of Delta-9-THC on cognition and psychosis are moderated by COMT Val(158)Met genotype, but the effects may in part be conditional on the additional presence of pre-existing psychosis liability. The association between cannabis and psychosis may represent higher order gene-environment and gene-gene interactions.

Common sequence variants have recently joined rare structural polymorphisms as genetic factors with strong evidence for association with schizophrenia. Here we extend our previous genome-wide association study and meta-analysis (totalling 7 946 cases and 19 036 controls) by examining an expanded set of variants using an enlarged follow-up sample (up to 10 260 cases and 23 500 controls). In addition to previously reported alleles in the major histocompatibility complex region, near neurogranin (NRGN) and in an intron of transcription factor 4 (TCF4), we find two novel variants showing genome-wide significant association: rs2312147[C], upstream of vaccinia-related kinase 2 (VRK2) [odds ratio (OR) = 1.09, P = 1.9 × 10(-9)] and rs4309482[A], between coiled-coiled domain containing 68 (CCDC68) and TCF4, about 400 kb from the previously described risk allele, but not accounted for by its association (OR = 1.09, P = 7.8 × 10(-9)).

Completed suicide is a major cause of death in bipolar disorder (BD) patients. The aim of this paper is to provide an overall review of the existing literature of completed suicide in BD patients, including clinical and genetic data We performed a systematic review of English and non-English articles published on MEDLINE/PubMed, PsycInfo and Cochrane database (1970–2017). Additional studies were identified by contacting clinical experts, searching bibliographies, major textbooks and website of World Health Organization. Initially we did a broad search for the association of bipolar disorder and suicide and we were narrowing the search in terms included “bipolar disorder” and “completed suicide”. Inclusion criteria were articles about completed suicide in patients with BD. Articles exclusively focusing on suicide attempts and suicidal behaviour have been excluded. We used PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) consensus for drafting this systematic review. The initial search generated 2806 articles and a total of 61 meeting our inclusion criteria. We reviewed epidemiological data, genetic factors, risk factors and treatment of completed suicide in BD. Suicide rates in BD vary between studies but our analyses show that they are approximately 20-30-fold greater than in general population. The highest risk of successful suicide was observed in BD-II subjects. The heritability of completed suicide is about 40% and some genes related to major neurotransmitter systems have been associated with suicide. Lithium is the only treatment that has shown anti-suicide potential. The most important limitation of the present review is the limited existing literature on completed suicide in BD. BD patients are at high risk for suicide. It is possible to identify some factors related to completed suicide, such as early onset, family history of suicide among first-degree relatives, previous attempted suicides, comorbidities and treatment. However it is necessary to promote research on this serious health problem.

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been observed in major depression. Normalization of HPA axis has been suggested to play a role in the mechanisms of action of antidepressants. Our aim was to investigate the influence of genetic variants in CRHR1, CRHR2, CRH-BP and FKBP5 genes on both the vulnerability for depression and the response to antidepressant treatment. The sample consisted of 159 depressive outpatients and 96 healthy controls of Spanish origin. Patients were assessed for clinical features including, among others, age of onset, seasonality or suicidal behavior. The episode was treated with citalopram and followed along 12 weeks. Severity of symptoms was evaluated at the inclusion and then monthly along the follow-up using a 21-item Hamilton Depression Rating Score (HDRS). SNPs were assayed using Applied Biosystems SNaP-Shot and TaqMan technology. rs110402, in CRHR1 gene, was associated with an increased risk to present a seasonal pattern and an early age of onset of the first depressive episode. Allele G carriers of rs2270007 of CRHR2 gene, showed a worse overall response to citalopram along time of follow-up (Genotype effect F = 7.45, P = 0.007). G allele carriers showed 2.93 increased risk (95% CI [1.24–6.90]) for non-responding at 4th week to citalopram treatment (χ2 = 7.59, df = 1, P = 0.006). On the light of the moderate sample size, associations based on the mentioned polymorphisms need to be considered with caution and require further replication studies in other samples. Variability at genes encoding proteins with a pivotal role in HPA axis regulation seems to influence i) the expression of severity variables of the depressive spectrum including early age of onset or a seasonal pattern and ii) the interindividual variation in clinical response to SSRI antidepressants.

Schizophrenia is a severe neuropsychiatric disorder with persistence of symptoms throughout adult life in most of the affected patients. This unfavorable course is associated with multiple episodes and residual symptoms, mainly negative symptoms and cognitive deficits. The neural diathesis-stress model proposes that psychosocial stress acts on a pre-existing vulnerability and thus triggers the symptoms of schizophrenia. Childhood trauma is a severe form of stress that renders individuals more vulnerable to developing schizophrenia; neurobiological effects of such trauma on the endocrine system and epigenetic mechanisms are discussed. Childhood trauma is associated with impaired working memory, executive function, verbal learning, and attention in schizophrenia patients, including those at ultra-high risk to develop psychosis. In these patients, higher levels of childhood trauma were correlated with higher levels of attenuated positive symptoms, general symptoms, and depressive symptoms; lower levels of global functioning; and poorer cognitive performance in visual episodic memory end executive functions. In this review, we discuss effects of specific gene variants that interact with childhood trauma in patients with schizophrenia and describe new findings on the brain structural and functional level. Additive effects between childhood trauma and brain-derived neurotrophic factor methionine carriers on volume loss of the hippocampal subregions cornu ammonis (CA)4/dentate gyrus and CA2/3 have been reported in schizophrenia patients. A functional magnetic resonance imaging study showed that childhood trauma exposure resulted in aberrant function of parietal areas involved in working memory and of visual cortical areas involved in attention. In a theory of mind task reflecting social cognition, childhood trauma was associated with activation of the posterior cingulate gyrus, precuneus, and dorsomedial prefrontal cortex in patients with schizophrenia. In addition, decreased connectivity was shown between the posterior cingulate/precuneus region and the amygdala in patients with high levels of physical neglect and sexual abuse during childhood, suggesting that disturbances in specific brain networks underlie cognitive abilities. Finally, we discuss some of the questionnaires that are commonly used to assess childhood trauma and outline possibilities to use recent biostatistical methods, such as machine learning, to analyze the resulting datasets.

Abstract Severe mental illnesses have been linked to white matter abnormalities, documented by postmortem studies. However, cause and effect have remained difficult to distinguish. CNP (2′,3′‐cyclic nucleotide 3′‐phosphodiesterase) is among the oligodendrocyte/myelin‐associated genes most robustly reduced on mRNA and protein level in brains of schizophrenic, bipolar or major depressive patients. This suggests that CNP reduction might be critical for a more general disease process and not restricted to a single diagnostic category. We show here that reduced expression of CNP is the primary cause of a distinct behavioural phenotype, seen only upon aging as an additional ‘pro‐inflammatory hit’. This phenotype is strikingly similar in Cnp heterozygous mice and patients with mental disease carrying the AA genotype at CNP SNP rs2070106. The characteristic features in both species with their partial CNP ‘loss‐of‐function’ genotype are best described as ‘catatonia‐depression’ syndrome. As a consequence of perturbed CNP expression, mice show secondary low‐grade inflammation/neurodegeneration. Analogously, in man, diffusion tensor imaging points to axonal loss in the frontal corpus callosum. To conclude, subtle white matter abnormalities inducing neurodegenerative changes can cause/amplify psychiatric diseases.

Schizophrenia is caused by a combination of genetic and environmental factors, as first evidenced by twin studies. Extensive efforts have been made to identify the genetic roots of schizophrenia, including large genome-wide association studies, but these yielded very small effect sizes for individual markers. In this study, we aimed to assess the relative contribution of genome-wide association study-derived genetic versus environmental risk factors to crucial determinants of schizophrenia severity: disease onset, disease severity, and socioeconomic measures.In this parallel analysis, we studied 750 male patients from the Göttingen Research Association for Schizophrenia (GRAS) dataset (Germany) with schizophrenia for whom both genome-wide coverage of single-nucleotide polymorphisms and deep clinical phenotyping data were available. Specifically, we investigated the potential effect of schizophrenia risk alleles as identified in the most recent large genome-wide association study versus the effects of environmental hazards (ie, perinatal brain insults, cannabis use, neurotrauma, psychotrauma, urbanicity, and migration), alone and upon accumulation, on age at disease onset, age at prodrome, symptom expression, and socioeconomic parameters.In this study, we could show that frequent environmental factors become a major risk for early schizophrenia onset when accumulated (prodrome begins up to 9 years earlier; p=2·9×10(-10)). In particular, cannabis use-an avoidable environmental risk factor-is highly significantly associated with earlier age at prodrome (p=3·8×10(-20)). By contrast, polygenic genome-wide association study risk scores did not have any detectable effects on schizophrenia phenotypes.These findings should be translated to preventive measures to reduce environmental risk factors, since age at onset of schizophrenia is a crucial determinant of an affected individual's fate and the total socioeconomic cost of the illness.German Research Foundation (Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain), Max Planck Society, Max Planck Förderstiftung, EXTRABRAIN EU-FP7, ERA-NET NEURON.

Lithium is a first-line mood stabilizer for the treatment of bipolar affective disorder (BPAD). However, the efficacy of lithium varies widely, with a nonresponse rate of up to 30%. Biological response markers are lacking. Genetic factors are thought to mediate treatment response to lithium, and there is a previously reported genetic overlap between BPAD and schizophrenia (SCZ).To test whether a polygenic score for SCZ is associated with treatment response to lithium in BPAD and to explore the potential molecular underpinnings of this association.A total of 2586 patients with BPAD who had undergone lithium treatment were genotyped and assessed for long-term response to treatment between 2008 and 2013. Weighted SCZ polygenic scores were computed at different P value thresholds using summary statistics from an international multicenter genome-wide association study (GWAS) of 36 989 individuals with SCZ and genotype data from patients with BPAD from the Consortium on Lithium Genetics. For functional exploration, a cross-trait meta-GWAS and pathway analysis was performed, combining GWAS summary statistics on SCZ and response to treatment with lithium. Data analysis was performed from September 2016 to February 2017.Treatment response to lithium was defined on both the categorical and continuous scales using the Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder score. The effect measures include odds ratios and the proportion of variance explained.Of the 2586 patients in the study (mean [SD] age, 47.2 [13.9] years), 1478 were women and 1108 were men. The polygenic score for SCZ was inversely associated with lithium treatment response in the categorical outcome, at a threshold P < 5 × 10-2. Patients with BPAD who had a low polygenic load for SCZ responded better to lithium, with odds ratios for lithium response ranging from 3.46 (95% CI, 1.42-8.41) at the first decile to 2.03 (95% CI, 0.86-4.81) at the ninth decile, compared with the patients in the 10th decile of SCZ risk. In the cross-trait meta-GWAS, 15 genetic loci that may have overlapping effects on lithium treatment response and susceptibility to SCZ were identified. Functional pathway and network analysis of these loci point to the HLA antigen complex and inflammatory cytokines.This study provides evidence for a negative association between high genetic loading for SCZ and poor response to lithium in patients with BPAD. These results suggest the potential for translational research aimed at personalized prescribing of lithium.

Importance No clinically applicable diagnostic test exists for severe mental disorders. Lipids harbor potential as disease markers. Objective To define a reproducible profile of lipid alterations in the blood plasma of patients with schizophrenia (SCZ) independent of demographic and environmental variables and to investigate its specificity in association with other psychiatric disorders, ie, major depressive disorder (MDD) and bipolar disorder (BPD). Design, Setting, and Participants This was a multicohort case-control diagnostic analysis involving plasma samples from psychiatric patients and control individuals collected between July 17, 2009, and May 18, 2018. Study participants were recruited as consecutive and volunteer samples at multiple inpatient and outpatient mental health hospitals in Western Europe (Germany and Austria [DE-AT]), China (CN), and Russia (RU). Individuals with DSM-IV or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnoses of SCZ, MDD, BPD, or a first psychotic episode, as well as age- and sex-matched healthy controls without a mental health–related diagnosis were included in the study. Samples and data were analyzed from January 2018 to September 2020. Main Outcomes and Measures Plasma lipidome composition was assessed using liquid chromatography coupled with untargeted mass spectrometry. Results Blood lipid levels were assessed in 980 individuals (mean [SD] age, 36 [13] years; 510 male individuals [52%]) diagnosed with SCZ, BPD, MDD, or those with a first psychotic episode and in 572 controls (mean [SD] age, 34 [13] years; 323 male individuals [56%]). A total of 77 lipids were found to be significantly altered between those with SCZ (n = 436) and controls (n = 478) in all 3 sample cohorts. Alterations were consistent between cohorts (CN and RU: [Pearson correlation] r = 0.75; DE-AT and CN: r = 0.78; DE-AT and RU: r = 0.82; P &amp;amp;lt; 10 −38 ). A lipid-based predictive model separated patients with SCZ from controls with high diagnostic ability (area under the receiver operating characteristic curve = 0.86-0.95). Lipidome alterations in BPD and MDD, assessed in 184 and 256 individuals, respectively, were found to be similar to those of SCZ (BPD: r = 0.89; MDD: r = 0.92; P &amp;amp;lt; 10 −79 ). Assessment of detected alterations in individuals with a first psychotic episode, as well as patients with SCZ not receiving medication, demonstrated only limited association with medication restricted to particular lipids. Conclusions and Relevance In this study, SCZ was accompanied by a reproducible profile of plasma lipidome alterations, not associated with symptom severity, medication, and demographic and environmental variables, and largely shared with BPD and MDD. This lipid alteration signature may represent a trait marker of severe psychiatric disorders, indicating its potential to be transformed into a clinically applicable testing procedure.

Lithium is regarded as the first-line treatment for bipolar disorder (BD), a severe and disabling mental health disorder that affects about 1% of the population worldwide. Nevertheless, lithium is not consistently effective, with only 30% of patients showing a favorable response to treatment. To provide personalized treatment options for bipolar patients, it is essential to identify prediction biomarkers such as polygenic scores. In this study, we developed a polygenic score for lithium treatment response (Li+PGS) in patients with BD. To gain further insights into lithium's possible molecular mechanism of action, we performed a genome-wide gene-based analysis. Using polygenic score modeling, via methods incorporating Bayesian regression and continuous shrinkage priors, Li+PGS was developed in the International Consortium of Lithium Genetics cohort (ConLi+Gen: N = 2367) and replicated in the combined PsyCourse (N = 89) and BipoLife (N = 102) studies. The associations of Li+PGS and lithium treatment response - defined in a continuous ALDA scale and a categorical outcome (good response vs. poor response) were tested using regression models, each adjusted for the covariates: age, sex, and the first four genetic principal components. Statistical significance was determined at P < 0.05. Li+PGS was positively associated with lithium treatment response in the ConLi+Gen cohort, in both the categorical (P = 9.8 × 10-12, R2 = 1.9%) and continuous (P = 6.4 × 10-9, R2 = 2.6%) outcomes. Compared to bipolar patients in the 1st decile of the risk distribution, individuals in the 10th decile had 3.47-fold (95%CI: 2.22-5.47) higher odds of responding favorably to lithium. The results were replicated in the independent cohorts for the categorical treatment outcome (P = 3.9 × 10-4, R2 = 0.9%), but not for the continuous outcome (P = 0.13). Gene-based analyses revealed 36 candidate genes that are enriched in biological pathways controlled by glutamate and acetylcholine. Li+PGS may be useful in the development of pharmacogenomic testing strategies by enabling a classification of bipolar patients according to their response to treatment.

The validation of nosological diagnoses in psychiatry remains a conundrum. Leonhard's (1979) nosology seems to be one of the few acceptable alternative categorical models to current DSM/ICD systems. We aimed to empirically validate Leonhard's four classes of psychoses: systematic schizophrenia (SSch), unsystematic (USch), cycloid psychosis (Cyclo), and manic-depressive illness (MDI) using a comprehensive set of explanatory validators. 243 patients with first-episode psychosis were followed between 10 and 31 years. A wide-ranging assessment was carried out by collecting data on antecedent, illness-related, concurrent, response to treatment, neuromotor abnormalities, and cognitive impairment variables. Compared with USch, Cyclo, and MDI, SSch displayed a pattern of impairments significantly larger across the seven blocks of explanatory variables. There were no significant differences between Cyclo and MDI in explanatory variables. Except for the majority of illness-onset features, USch displayed more substantial abnormalities in the explanatory variables than Cyclo and MDI. SSch and MDI showed higher percentages of correctly classified patients than USch and Cyclo in linear discriminant analyses. Partial validation of Leonhard's classification was found. SSch showed differences in explanatory variables with respect to Cyclo and MDI. USch showed also significant differences in explanatory variables regarding Cyclo and MDI, although with a lower strength than SSch. There was strong empirical evidence of the separation between both Leonhard's schizophrenia subtypes; however, the distinction between the Cyclo and MDI groups was not empirically supported. A mild to moderate discriminative ability between Leonhard's subtypes on the basis of explanatory blocks of variables was observed.

Abstract Gene–environment interactions involving the catechol‐ O ‐methyltransferase Val 158 Met polymorphism (COMT Val158Met ) have been implicated in the causation of psychosis. Evidence from general population studies suggests that Met/Met subjects are sensitive to stress, a trait associated with psychosis. We hypothesized that the Met allele would moderate the effects of stress on negative affect (NA) in controls, and on NA and psychosis in patients with a psychotic disorder. Thirty‐one patients with a psychotic disorder and comorbid cannabis misuse and 25 healthy cannabis users were studied with the experience sampling method (ESM), a structured diary technique assessing current context and emotional and psychotic experiences in daily life. A significant interaction between COMT Val158Met genotype and ESM stress in the model of NA was found for patients (interaction χ 2 = 7.4, P = 0.02), but not for controls (interaction χ 2 = 3.8, P = 0.15). In the model of ESM psychosis, a significant interaction between COMT Val158Met genotype and ESM stress was also apparent (interaction χ 2 = 11.6, P &lt; 0.01), with Met/Met patients showing the largest increase in psychotic experiences as well as NA in reaction to ESM stress. The findings suggest that the COMT Val158Met polymorphism moderates affective and psychotic responses to stress in patients with psychosis, providing evidence for gene–environment interaction mechanisms in the formation of psychotic symptoms. © 2007 Wiley‐Liss, Inc.

A functional polymorphism in the catechol-o-methyltransferase gene (COMT Val(158)Met) may moderate the psychosis-inducing effects of cannabis. In order to extend this finding to dynamic effects in the flow of daily life, a momentary assessment study of psychotic symptoms in response to cannabis use was conducted.The experience sampling technique was used to collect data on cannabis use and occurrence of symptoms in daily life in patients with a psychotic disorder (n = 31) and healthy controls (n = 25).Carriers of the COMT Val(158)Met Val allele, but not subjects with the Met/Met genotype, showed an increase in hallucinations after cannabis exposure, conditional on prior evidence of psychometric psychosis liability.The findings confirm that in people with psychometric evidence of psychosis liability, COMT Val(158)Met genotype moderates the association between cannabis and psychotic phenomena in the flow of daily life.

Epidemiological and genetic data support the notion that schizophrenia and bipolar disorder share genetic risk factors. In our previous genome-wide association study, meta-analysis and follow-up (totaling as many as 18 206 cases and 42 536 controls), we identified four loci showing genome-wide significant association with schizophrenia. Here we consider a mixed schizophrenia and bipolar disorder (psychosis) phenotype (addition of 7469 bipolar disorder cases, 1535 schizophrenia cases, 333 other psychosis cases, 808 unaffected family members and 46 160 controls). Combined analysis reveals a novel variant at 16p11.2 showing genome-wide significant association (rs4583255[T]; odds ratio=1.08; P=6.6 × 10−11). The new variant is located within a 593-kb region that substantially increases risk of psychosis when duplicated. In line with the association of the duplication with reduced body mass index (BMI), rs4583255[T] is also associated with lower BMI (P=0.0039 in the public GIANT consortium data set; P=0.00047 in 22 651 additional Icelanders).

Schizophrenia is the collective term for a heterogeneous group of mental disorders with a still obscure biological basis. In particular, the specific contribution of risk or candidate gene variants to the complex schizophrenic phenotype is largely unknown.To prepare the ground for a novel "phenomics" approach, a unique schizophrenia patient database was established by GRAS (Göttingen Research Association for Schizophrenia), designed to allow association of genetic information with quantifiable phenotypes.Because synaptic dysfunction plays a key role in schizophrenia, the complexin 2 gene (CPLX2) was examined in the first phenotype-based genetic association study (PGAS) of GRAS [corrected]Subsequent to a classic case-control approach, we analyzed the contribution of CPLX2 polymorphisms to discrete cognitive domains within the schizophrenic population. To gain mechanistic insight into how certain CPLX2 variants influence gene expression and function, peripheral blood mononuclear cells of patients, Cplx -null mutant mice, and transfected cells were investigated.Coordinating research center (Max Planck Institute of Experimental Medicine) and 23 collaborating psychiatric centers all over Germany.One thousand seventy-one patients with schizophrenia (DSM-IV) examined by an invariant investigator team, resulting in the GRAS database with more than 3000 phenotypic data points per patient, and 1079 healthy control subjects of comparable ethnicity. Main Outcome Measure Cognitive performance including executive functioning, reasoning, and verbal learning/memory.Six single-nucleotide polymorphisms, distributed over the whole CPLX2 gene, were found to be highly associated with current cognition of schizophrenic subjects but only marginally with premorbid intelligence. Correspondingly, in Cplx2 -null mutant mice, prominent cognitive loss of function was obtained only in combination with a minor brain lesion applied during puberty, modeling a clinically relevant environmental risk ("second hit") for schizophrenia. In the human CPLX2 gene, 1 of the identified 6 cognition-relevant single-nucleotide polymorphisms, rs3822674 in the 3' untranslated region, was detected to influence microRNA-498 binding and gene expression. The same marker was associated with differential expression of CPLX2 in peripheral blood mononuclear cells.The PGAS allows identification of marker-associated clinical/biological traits. Current cognitive performance in schizophrenic patients is modified by CPLX2 variants modulating posttranscriptional gene expression.

Abstract Recent improvements in high-throughput proteomic approaches are likely to constitute an essential advance in biomarker discovery, holding promise for improved personalized care and drug development. These methodologies have been applied to study multivariate protein patterns and provide valuable data of peripheral tissues. To highlight findings of the last decade for three of the most common psychiatric disorders, namely schizophrenia (SZ), bipolar disorder (BD), and major depressive disorder (MDD), we queried PubMed. Here we delve into the findings from thirty studies, which used proteomics and multiplex immunoassay approaches for peripheral blood biomarker exploration. In an explorative approach, we ran enrichment analyses in peripheral blood according to these results and ascertained the overlap between proteomic findings and genetic loci identified in genome-wide association studies (GWAS). The studies we appraised demonstrate that proteomics for psychiatric research has been heterogeneous in aims and methods and limited by insufficient sample sizes, poorly defined case definitions, methodological inhomogeneity, and confounding results constraining the conclusions that can be extracted from them. Here, we discuss possibilities for overcoming methodological challenges for the implementation of proteomic signatures in psychiatric diagnosis and offer an outlook for future investigations. To fulfill the promise of proteomics in mental disease diagnostics, future research will need large, well-defined cohorts in combination with state-of-the-art technologies.

Preliminary studies suggest that, besides improving cognition, aerobic exercise might increase hippocampal volume in schizophrenia patients; however, results are not consistent. Individual mechanisms of volume changes are unknown but might be connected to the load of risk genes. Genome-wide association studies have uncovered the polygenic architecture of schizophrenia. The secondary analysis presented here aimed to determine the modulatory role of schizophrenia polygenic risk scores (PRSs) on volume changes in the total hippocampus and cornu ammonis (CA) 1, CA2/3, CA4/dentate gyrus (DG) and subiculum over time. We studied 20 multi-episode schizophrenia patients and 23 healthy controls who performed aerobic exercise (endurance training) combined with cognitive remediation for 3 months and 21 multi-episode schizophrenia patients allocated to a control intervention (table soccer) combined with cognitive remediation. Magnetic resonance imaging-based assessments were performed at baseline and after 3 months with FreeSurfer. No effects of PRSs were found on total hippocampal volume change. Subfield analyses showed that the volume changes between baseline and 3 months in the left CA4/DG were significantly influenced by PRSs in schizophrenia patients performing aerobic exercise. A larger genetic risk burden was associated with a less pronounced volume increase or a decrease in volume over the course of the exercise intervention. Results of exploratory enrichment analyses reinforced the notion of genetic risk factors modulating biological processes tightly related to synaptic ion channel activity, calcium signaling, glutamate signaling and regulation of cell morphogenesis. We hypothesize that a high polygenic risk may negatively influence neuroplasticity in CA4/DG during aerobic exercise in schizophrenia.

Religious delusions are a common symptom in patients experiencing psychosis, with varying prevalence rates of religious delusions across cultures and societies. To enhance our knowledge of this distinct psychotic feature, we investigated the mutually-adjusted association of genetic and environmental factors with occurrence of religious delusions.We studied 262 adult German patients with schizophrenia or schizoaffective disorder. Association with lifetime occurrence of religious delusions was tested by multiple logistic regression for the following putative predictors: self-reported degree of religious activity, DSM-IV diagnosis, sex, age, education level, marital status, presence of acute delusion at the time of interview and an individual polygenic schizophrenia-risk score (SZ-PRS, available in 239 subjects).Of the 262 patients, 101 (39%) had experienced religious delusions. The risk of experiencing religious delusions was significantly increased in patients with strong religious activity compared to patients without religious affiliation (OR = 3.6, p = 0.010). Low or moderate religious activity had no significant effect. The same analysis including the SZ-PRS confirmed the effect of high religious activity on occurrence of religious delusions (OR = 4.1, p = 0.008). Additionally, the risk of experiencing religious delusions increased with higher SZ-PRS (OR 1.4, p = 0.020, using pT = 0.05 for SZ-PRS calculation). None of the other variables were significantly associated with lifetime occurrence of religious delusions.Our results suggest that strong religious activity and high SZ-PRS are independent risk factors for the occurrence of religious delusions in schizophrenia and schizoaffective disorder.

In current diagnostic systems, schizophrenia and bipolar disorder are still conceptualized as distinct categorical entities. Recently, both clinical and genomic evidence have challenged this Kraepelinian dichotomy. There are only few longitudinal studies addressing potential overlaps between these conditions. Here, we present design and first results of the PsyCourse study ( N = 891 individuals at baseline), an ongoing transdiagnostic study of the affective‐to‐psychotic continuum that combines longitudinal deep phenotyping and dimensional assessment of psychopathology with an extensive collection of biomaterial. To provide an initial characterization of the PsyCourse study sample, we compare two broad diagnostic groups defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) classification system, that is, predominantly affective ( n = 367 individuals) versus predominantly psychotic disorders ( n = 524 individuals). Depressive, manic, and psychotic symptoms as well as global functioning over time were contrasted using linear mixed models. Furthermore, we explored the effects of polygenic risk scores for schizophrenia on diagnostic group membership and addressed their effects on nonparticipation in follow‐up visits. While phenotypic results confirmed expected differences in current psychotic symptoms and global functioning, both manic and depressive symptoms did not vary between both groups after correction for multiple testing. Polygenic risk scores for schizophrenia significantly explained part of the variability of diagnostic group. The PsyCourse study presents a unique resource to research the complex relationships of psychopathology and biology in severe mental disorders not confined to traditional diagnostic boundaries and is open for collaborations.

Lithium is a first-line medication for bipolar disorder (BD), but only one in three patients respond optimally to the drug. Since evidence shows a strong clinical and genetic overlap between depression and bipolar disorder, we investigated whether a polygenic susceptibility to major depression is associated with response to lithium treatment in patients with BD. Weighted polygenic scores (PGSs) were computed for major depression (MD) at different GWAS p value thresholds using genetic data obtained from 2586 bipolar patients who received lithium treatment and took part in the Consortium on Lithium Genetics (ConLi+Gen) study. Summary statistics from genome-wide association studies in MD (135,458 cases and 344,901 controls) from the Psychiatric Genomics Consortium (PGC) were used for PGS weighting. Response to lithium treatment was defined by continuous scores and categorical outcome (responders versus non-responders) using measurements on the Alda scale. Associations between PGSs of MD and lithium treatment response were assessed using a linear and binary logistic regression modeling for the continuous and categorical outcomes, respectively. The analysis was performed for the entire cohort, and for European and Asian sub-samples. The PGSs for MD were significantly associated with lithium treatment response in multi-ethnic, European or Asian populations, at various p value thresholds. Bipolar patients with a low polygenic load for MD were more likely to respond well to lithium, compared to those patients with high polygenic load [lowest vs highest PGS quartiles, multi-ethnic sample: OR = 1.54 (95% CI: 1.18-2.01) and European sample: OR = 1.75 (95% CI: 1.30-2.36)]. While our analysis in the Asian sample found equivalent effect size in the same direction: OR = 1.71 (95% CI: 0.61-4.90), this was not statistically significant. Using PGS decile comparison, we found a similar trend of association between a high genetic loading for MD and lower response to lithium. Our findings underscore the genetic contribution to lithium response in BD and support the emerging concept of a lithium-responsive biotype in BD.

This study examines the association between insulin resistance, schizophrenia polygenic risk, and treatment outcomes in first-episode, antipsychotic-naive patients with schizophrenia.

<h3>Importance</h3> Identifying psychosis subgroups could improve clinical and research precision. Research has focused on symptom subgroups, but there is a need to consider a broader clinical spectrum, disentangle illness trajectories, and investigate genetic associations. <h3>Objective</h3> To detect psychosis subgroups using data-driven methods and examine their illness courses over 1.5 years and polygenic scores for schizophrenia, bipolar disorder, major depression disorder, and educational achievement. <h3>Design, Setting, and Participants</h3> This ongoing multisite, naturalistic, longitudinal (6-month intervals) cohort study began in January 2012 across 18 sites. Data from a referred sample of 1223 individuals (765 in the discovery sample and 458 in the validation sample) with<i>DSM</i>-<i>IV</i>diagnoses of schizophrenia, bipolar affective disorder (I/II), schizoaffective disorder, schizophreniform disorder, and brief psychotic disorder were collected from secondary and tertiary care sites. Discovery data were extracted in September 2016 and analyzed from November 2016 to January 2018, and prospective validation data were extracted in October 2018 and analyzed from January to May 2019. <h3>Main Outcomes and Measures</h3> A clinical battery of 188 variables measuring demographic characteristics, clinical history, symptoms, functioning, and cognition was decomposed using nonnegative matrix factorization clustering. Subtype-specific illness courses were compared with mixed models and polygenic scores with analysis of covariance. Supervised learning was used to replicate results in validation data with the most reliably discriminative 45 variables. <h3>Results</h3> Of the 765 individuals in the discovery sample, 341 (44.6%) were women, and the mean (SD) age was 42.7 (12.9) years. Five subgroups were found and labeled as affective psychosis (n = 252), suicidal psychosis (n = 44), depressive psychosis (n = 131), high-functioning psychosis (n = 252), and severe psychosis (n = 86). Illness courses with significant quadratic interaction terms were found for psychosis symptoms (<i>R</i>² = 0.41; 95% CI, 0.38-0.44), depression symptoms (<i>R</i>² = 0.28; 95% CI, 0.25-0.32), global functioning (<i>R</i>² = 0.16; 95% CI, 0.14-0.20), and quality of life (<i>R</i>² = 0.20; 95% CI, 0.17-0.23). The depressive and severe psychosis subgroups exhibited the lowest functioning and quadratic illness courses with partial recovery followed by reoccurrence of severe illness. Differences were found for educational attainment polygenic scores (mean [SD] partial η² = 0.014 [0.003]) but not for diagnostic polygenic risk. Results were largely replicated in the validation cohort. <h3>Conclusions and Relevance</h3> Psychosis subgroups were detected with distinctive clinical signatures and illness courses and specificity for a nondiagnostic genetic marker. New data-driven clinical approaches are important for future psychosis taxonomies. The findings suggest a need to consider short-term to medium-term service provision to restore functioning in patients stratified into the depressive and severe psychosis subgroups.

Abstract Lithium is the gold standard therapy for Bipolar Disorder (BD) but its effectiveness differs widely between individuals. The molecular mechanisms underlying treatment response heterogeneity are not well understood, and personalized treatment in BD remains elusive. Genetic analyses of the lithium treatment response phenotype may generate novel molecular insights into lithium’s therapeutic mechanisms and lead to testable hypotheses to improve BD management and outcomes. We used fixed effect meta-analysis techniques to develop meta-analytic polygenic risk scores (MET-PRS) from combinations of highly correlated psychiatric traits, namely schizophrenia (SCZ), major depression (MD) and bipolar disorder (BD). We compared the effects of cross-disorder MET-PRS and single genetic trait PRS on lithium response. For the PRS analyses, we included clinical data on lithium treatment response and genetic information for n = 2283 BD cases from the International Consortium on Lithium Genetics (ConLi + Gen; www.ConLiGen.org ). Higher SCZ and MD PRSs were associated with poorer lithium treatment response whereas BD-PRS had no association with treatment outcome. The combined MET2-PRS comprising of SCZ and MD variants (MET2-PRS) and a model using SCZ and MD-PRS sequentially improved response prediction, compared to single-disorder PRS or to a combined score using all three traits (MET3-PRS). Patients in the highest decile for MET2-PRS loading had 2.5 times higher odds of being classified as poor responders than patients with the lowest decile MET2-PRS scores. An exploratory functional pathway analysis of top MET2-PRS variants was conducted. Findings may inform the development of future testing strategies for personalized lithium prescribing in BD.

Major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia spectrum disorders (SZ) exhibit considerable phenotypic and genetic overlap. However, the contribution of genetic factors to their shared psychopathological symptom dimensions remains unclear. The present exploratory study investigated genetic contributions to the symptom dimensions "Depression", "Negative syndrome", "Positive formal thought disorder", "Paranoid-hallucinatory syndrome", and "Increased appetite" in a transdiagnostic subset of the German FOR2107 cohort (n = 1042 patients with MDD, BD, or SZ). As replication cohort, a subset of the German/Austrian PsyCourse study (n = 816 patients with MDD, BD, or SZ) was employed. First, the relationship between symptom dimensions and common variants associated with MDD, BD, and SZ was investigated via polygenic risk score (PRS) association analyses, with disorder-specific PRS as predictors and symptom dimensions as outcomes. In the FOR2107 study sample, PRS for BD and SZ were positively associated with "Positive formal thought disorder", the PRS for SZ was positively associated with "Paranoid-hallucinatory syndrome", and the PRS for BD was negatively associated with "Depression". The effects of PRS for SZ were replicated in PsyCourse. No significant associations were observed for the MDD PRS. Second, genome-wide association studies (GWAS) were performed for the five symptom dimensions. No genome-wide significant associations and no replicable suggestive associations (p < 1e-6 in the GWAS) were identified. In summary, our results suggest that, similar to diagnostic categories, transdiagnostic psychiatric symptom dimensions are attributable to polygenic contributions with small effect sizes. Further studies in larger thoroughly phenotyped psychiatric cohorts are required to elucidate the genetic factors that shape psychopathological symptom dimensions.

Monoamine oxidase A (MAOA) has been suggested to be involved in human behaviour and physiology due to its key role in the metabolism of several different biological amines including the neurotransmitters serotonin, norepinephrin and dopamine.Recently, a 30 bp repeat in the MAOA gene promoter (uMAOA) has been demonstrated to be polymorphic and to affect transcriptional activity. In the context of an association case-control study design, we analysed the uMAOA polymorphism in 389 unrelated patients affected by severe mood disorders (88 bipolar subjects and 301 major depressive individuals) and in 156 controls. No association was found between the uMAOA locus and bipolar disorder or major depression. However, an increase of high-activity uMAOA alleles was found in major depression female patients presenting a seasonal pattern (chi2=3.013, P=0.05) or psychotic symptoms in their episodes (chi2=2.679, P=0.07). In female bipolar disorder patients, long alleles were associated with longest times of admission (F=4.604, P=0.037). A trend for association with seasonal pattern was also defined in this group (data not corrected for multiple testing). Our results suggest that MAOA gene variation may modulate the expression of some clinical aspects of severe mood disorders, especially in females, and support the existence of a genetic and aetiologic heterogeneity underlying the diagnoses of bipolar disorder and major depression.

Abstract KCNN3 , encoding the small conductance calcium‐activated potassium channel SK3, harbours a polymorphic CAG repeat in the amino‐terminal coding region with yet unproven function. Hypothesizing that KCNN3 genotypes do not influence susceptibility to schizophrenia but modify its phenotype, we explored their contribution to specific schizophrenic symptoms. Using the Göttingen Research Association for Schizophrenia (GRAS) data collection of schizophrenic patients ( n = 1074), we performed a phenotype‐based genetic association study (PGAS) of KCNN3 . We show that long CAG repeats in the schizophrenic sample are specifically associated with better performance in higher cognitive tasks, comprising the capacity to discriminate, select and execute ( p &lt; 0.0001). Long repeats reduce SK3 channel function, as we demonstrate by patch‐clamping of transfected HEK293 cells. In contrast, modelling the opposite in mice, i.e. KCNN3 overexpression/channel hyperfunction, leads to selective deficits in higher brain functions comparable to those influenced by SK3 conductance in humans. To conclude, KCNN3 genotypes modify cognitive performance, shown here in a large sample of schizophrenic patients. Reduction of SK3 function may constitute a pharmacological target to improve cognition in schizophrenia and other conditions with cognitive impairment. →See accompanying Closeup by Anil K Malhotra http://dx.doi.org/10.1002/emmm.201100137

In a first genome-wide association study (GWAS) approach to anti-Borrelia seropositivity, we identified two significant single nucleotide polymorphisms (SNPs) (rs17850869, P = 4.17E-09; rs41289586, P = 7.18E-08). Both markers, located on chromosomes 16 and 3, respectively, are within or close to genes previously connected to spinocerebellar ataxia. The risk SNP rs41289586 represents a missense variant (R263H) of anoctamin 10 (ANO10), a member of a protein family encoding Cl− channels and phospholipid scramblases. ANO10 augments volume-regulated Cl− currents (IHypo) in Xenopus oocytes, HEK293 cells, lymphocytes and macrophages and controls volume regulation by enhancing regulatory volume decrease (RVD). ANO10 supports migration of macrophages and phagocytosis of spirochetes. The R263H variant is inhibitory on IHypo, RVD and intracellular Ca2+ signals, which may delay spirochete clearance, thereby sensitizing adaptive immunity. Our data demonstrate for the first time that ANO10 has a central role in innate immune defense against Borrelia infection.

Abstract Background Lithium is recommended as a first line treatment for bipolar disorders. However, only 30% of patients show an optimal outcome and variability in lithium response and tolerability is poorly understood. It remains difficult for clinicians to reliably predict which patients will benefit without recourse to a lengthy treatment trial. Greater precision in the early identification of individuals who are likely to respond to lithium is a significant unmet clinical need. Structure The H2020-funded Response to Lithium Network (R-LiNK; http://www.r-link.eu.com/ ) will undertake a prospective cohort study of over 300 individuals with bipolar-I-disorder who have agreed to commence a trial of lithium treatment following a recommendation by their treating clinician. The study aims to examine the early prediction of lithium response, non-response and tolerability by combining systematic clinical syndrome subtyping with examination of multi-modal biomarkers (or biosignatures), including omics, neuroimaging, and actigraphy, etc. Individuals will be followed up for 24 months and an independent panel will assess and classify each participants’ response to lithium according to predefined criteria that consider evidence of relapse, recurrence, remission, changes in illness activity or treatment failure (e.g. stopping lithium; new prescriptions of other mood stabilizers) and exposure to lithium. Novel elements of this study include the recruitment of a large, multinational, clinically representative sample specifically for the purpose of studying candidate biomarkers and biosignatures; the application of lithium-7 magnetic resonance imaging to explore the distribution of lithium in the brain; development of a digital phenotype (using actigraphy and ecological momentary assessment) to monitor daily variability in symptoms; and economic modelling of the cost-effectiveness of introducing biomarker tests for the customisation of lithium treatment into clinical practice. Also, study participants with sub-optimal medication adherence will be offered brief interventions (which can be delivered via a clinician or smartphone app) to enhance treatment engagement and to minimize confounding of lithium non-response with non-adherence. Conclusions The paper outlines the rationale, design and methodology of the first study being undertaken by the newly established R-LiNK collaboration and describes how the project may help to refine the clinical response phenotype and could translate into the personalization of lithium treatment.

Individuals with a first episode of psychosis (FEP) show rapid weight gain during the first months of treatment, which is associated with a reduction in general physical health. Although genetics is assumed to be a significant contributor to weight gain, its exact role is unknown.We assembled a population-based FEP cohort of 381 individuals that was split into a Training (n = 224) set and a Validation (n = 157) set to calculate the polygenic risk score (PRS) in a two-step process. In parallel, we obtained reference genome-wide association studies for body mass index (BMI) and schizophrenia (SCZ) to examine the pleiotropic landscape between the two traits. BMI PRSs were added to linear models that included sociodemographic and clinical variables to predict BMI increase (∆BMI) in the Validation set.The results confirmed considerable shared genetic susceptibility for the two traits involving 449 near-independent genomic loci. The inclusion of BMI PRSs significantly improved the prediction of ∆BMI at 12 months after the onset of antipsychotic treatment by 49.4% compared to a clinical model. In addition, we demonstrated that the PRS containing pleiotropic information between BMI and SCZ predicted ∆BMI better at 3 (12.2%) and 12 months (53.2%).We prove for the first time that genetic factors play a key role in determining ∆BMI during the FEP. This finding has important clinical implications for the early identification of individuals most vulnerable to weight gain and highlights the importance of examining genetic pleiotropy in the context of medically important comorbidities for predicting future outcomes.

Existing guidelines recommend psychopharmacological treatment for the management of schizophrenia and bipolar disorder as part of holistic treatment concepts. About half of the patients do not take their medication regularly, although treatment adherence can prevent exacerbations and re-hospitalizations. To date, the relationship between medication adherence and cognitive performance is understudied. Therefore, this study investigated the relationship between medication adherence and cognitive performance by analyzing the data of 862 participants with schizophrenia-spectrum and bipolar disorders (mean [SD] age, 41.9 [12.48] years; 44.8% female) from a multicenter study (PsyCourse Study). Z-scores for three cognitive domains were calculated, global functioning was measured with the Global Assessment of Functioning Scale, and adherence was assessed by a self-rating questionnaire. We evaluated four multiple linear regression models and built three clusters with hierarchical cluster analyses. Higher adherence behavior (p < 0.001) was associated with better global functioning but showed no impact on the cognitive domains learning and memory, executive function, and psychomotor speed. The hierarchical cluster analysis resulted in three clusters with different cognitive performances, but patients in all clusters showed similar adherence behavior. The study identified cognitive subgroups independent of diagnoses, but no differences were found in the adherence behavior of the patients in these new clusters. In summary, medication adherence was associated with global but not cognitive functioning in patients with schizophrenia-spectrum and bipolar disorders. In both diagnostic groups, cognitive function might be influenced by various factors but not medication adherence.

Schizophrenia and affective psychoses are severe and prevalent psychiatric disorders described in all cultures and populations. Whether these functional psychoses are two distinct disorders, or are closely related in aetiology, has been debated in the literature during the last century.1–4 Several studies have suggested that schizophrenia and bipolar disorder are on a continuum of liability. Psychopathological dimensions and psychiatric symptoms shared by both groups of patients would be compatible with this overlap.5 Likewise, other risk factors, such as cerebral ventricle enlargement,6 markers of prenatal suffering,7 or life events,8 have been described in both mental disorders. Recent molecular linkage studies have suggested the possible existence of shared disease loci for both disorders.9 Of special interest are the family studies showing that first degree relatives of bipolar patients have a three times increased risk for schizophrenia compared with first degree relatives of controls.10,11 These data suggest the presence of a common genetic risk background in both disorders. However, it should be noted that other family studies have not been able to replicate these latter results.12,13 Over the last decade, several studies have reported an imbalance in pro-inflammatory/anti-inflammatory cytokines or their soluble receptors level in plasma or cerebrospinal fluid of schizophrenic and bipolar disorder patients.14,15 These results have been replicated by recent studies in both diagnostic groups.16,17 Genes coding for some of these cytokines are located on the IL-1 cluster within chromosome 2q13. This cluster contains nine genes of the IL-1 family of cytokines ( IL-1A , IL-1B , IL-1RN , and IL-1F5–F10 ).18 Several polymorphic variants of these genes have been associated with human diseases.19 The IL-1β gene ( IL-1B ) consists of seven exons with an extension of 7 kb and codes for a precursor form (proIL-1β) …

Interleukin-1beta (IL-1beta), as well as other cytokines, has been classically implicated in the pathophysiology of major psychiatric disorders such as schizophrenia and major depression, and recent studies have implicated the IL-1beta gene and schizophrenia. Nevertheless, new approaches to this complex phenotype are necessary to clarify the risk conferred by this gene, either to the disorder or to its clinical manifestations. The aim of the present study was to explore the effect of a genetic polymorphism of the promoter region of the IL-1beta gene, in schizophrenia defined with: (i) a categorical diagnosis and (ii) a multidimensional symptom approach. We studied 356 individuals from 89 nuclear families consisting of one affected individual and the unaffected father, mother, and sib, in a family-based association study design. We find a trend for biased transmission of allele 2 from heterozygous parents to affected offspring, categorically defined (P = 0.07). This tendency was not observed in the healthy offspring. Using a multidimensional symptom approach to the diagnosis, the association was confirmed in psychotic patients showing the depressive symptom-dimension (P = 0.02).

Twin, family and recent molecular studies support the hypothesis of genetic overlapping between schizophrenia and bipolar disorder. Brain structural features shared by both psychiatric disorders might be the phenotypic expression of a common genetic risk background. Interleukin-1 (IL-1) cluster (chromosome 2q13) genetic variability, previously associated with an increased risk both for schizophrenia and for bipolar disorder, has been also associated with gray matter (GM) deficits, ventricular enlargement and hypoactivity of prefrontal cortex in schizophrenia. The aim of the present study was to analyze the influence of IL-1 cluster on brain morphology in bipolar disorder. Genetic variability at IL-1B and IL-1RN genes was analyzed in 20 DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition) bipolar patients. Magnetic resonance imaging (MRI) measurements were obtained for whole-brain GM and white matter, dorsolateral prefrontal cortex (DLPFC), superior temporal gyrus, hippocampus and lateral ventricles. MRI data were corrected for age and cranial size using regression parameters from a group of 45 healthy subjects. A -511C/T polymorphism (rs16944) of IL-1B gene was associated with whole-brain GM deficits (P = 0.031) and left DLPFCGM deficits (P = 0.047) in bipolar disorder patients. These findings support the hypothesis of IL-1 cluster variability as a shared genetic risk factor contributing to GM deficits both in bipolar disorder and in schizophrenia. Independent replication in larger samples would be of interest to confirm these results.

Abstract Background Schizophrenia is the collective term for an exclusively clinically diagnosed, heterogeneous group of mental disorders with still obscure biological roots. Based on the assumption that valuable information about relevant genetic and environmental disease mechanisms can be obtained by association studies on patient cohorts of ≥ 1000 patients, if performed on detailed clinical datasets and quantifiable biological readouts, we generated a new schizophrenia data base, the GRAS (Göttingen Research Association for Schizophrenia) data collection. GRAS is the necessary ground to study genetic causes of the schizophrenic phenotype in a 'phenotype-based genetic association study' (PGAS). This approach is different from and complementary to the genome-wide association studies (GWAS) on schizophrenia. Methods For this purpose, 1085 patients were recruited between 2005 and 2010 by an invariable team of traveling investigators in a cross-sectional field study that comprised 23 German psychiatric hospitals. Additionally, chart records and discharge letters of all patients were collected. Results The corresponding dataset extracted and presented in form of an overview here, comprises biographic information, disease history, medication including side effects, and results of comprehensive cross-sectional psychopathological, neuropsychological, and neurological examinations. With &gt;3000 data points per schizophrenic subject, this data base of living patients, who are also accessible for follow-up studies, provides a wide-ranging and standardized phenotype characterization of as yet unprecedented detail. Conclusions The GRAS data base will serve as prerequisite for PGAS, a novel approach to better understanding 'the schizophrenias' through exploring the contribution of genetic variation to the schizophrenic phenotypes.

A recent publication reported an exciting polygenic effect of schizophrenia (SCZ) risk variants, identified by a large genome-wide association study (GWAS), on total brain and white matter volumes in schizophrenic patients and, even more prominently, in healthy subjects. The aim of the present work was to replicate and then potentially extend these findings. According to the original publication, polygenic risk scores-using single nucleotide polymorphism (SNP) information of SCZ GWAS-(polygenic SCZ risk scores; PSS) were calculated in 122 healthy subjects, enrolled in a structural magnetic resonance imaging (MRI) study. These scores were computed based on P-values and odds ratios available through the Psychiatric GWAS Consortium. In addition, polygenic white matter scores (PWM) were calculated, using the respective SNP subset in the original publication. None of the polygenic scores, either PSS or PWM, were found to be associated with total brain, white matter or gray matter volume in our replicate sample. Minor differences between the original and the present study that might have contributed to lack of reproducibility (but unlikely explain it fully), are number of subjects, ethnicity, age distribution, array technology, SNP imputation quality and MRI scanner type. In contrast to the original publication, our results do not reveal the slightest signal of association of the described sets of GWAS-identified SCZ risk variants with brain volumes in adults. Caution is indicated in interpreting studies building on polygenic risk scores without replication sample.

Cognitive impairment is a key feature in patients with psychotic disorders. The Montreal Cognitive Assessment (MoCA) is a brief tool that has been shown to be effective in identifying mild cognitive impairment and early dementia. This study explores the usefulness of this instrument to detect cognitive impairment in long-term psychotic disorders. One hundred-forty stabilized patients were re-evaluated more than 15 years after a First Episode of Psychosis (FEP). Patients were psychopathologically assessed, and the MoCA test and MATRICS Consensus Cognitive Battery (MCCB) were administered. Two cut-off scores for cognitive impairment using the MCCB were applied (T score <40 and < 30). Concurrent validation was found between the total scores of the MoCA and MCCB. We also found significant associations between 5 out of 7 MoCA subtests (visuospatial-executive, attention, language, abstraction and delayed recall) and MCCB subtests but not for the naming and orientation MoCA subtests. Receiver operating characteristic (ROC) analysis suggested a <25 cut-off for cognitive impairment instead of the original <26. Our results suggest that the MoCA test is a useful screening instrument for assessing cognitive impairment in psychotic patients and has some advantages over other available instruments, such as its ease-of-use and short administration time.

Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = -0.34 years, s.e. = 0.08), major depression (β = -0.34 years, s.e. = 0.08), schizophrenia (β = -0.39 years, s.e. = 0.08), and educational attainment (β = -0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.

Response to lithium in patients with bipolar disorder is associated with clinical and transdiagnostic genetic factors. The predictive combination of these variables might help clinicians better predict which patients will respond to lithium treatment.To use a combination of transdiagnostic genetic and clinical factors to predict lithium response in patients with bipolar disorder.This study utilised genetic and clinical data (n = 1034) collected as part of the International Consortium on Lithium Genetics (ConLi+Gen) project. Polygenic risk scores (PRS) were computed for schizophrenia and major depressive disorder, and then combined with clinical variables using a cross-validated machine-learning regression approach. Unimodal, multimodal and genetically stratified models were trained and validated using ridge, elastic net and random forest regression on 692 patients with bipolar disorder from ten study sites using leave-site-out cross-validation. All models were then tested on an independent test set of 342 patients. The best performing models were then tested in a classification framework.The best performing linear model explained 5.1% (P = 0.0001) of variance in lithium response and was composed of clinical variables, PRS variables and interaction terms between them. The best performing non-linear model used only clinical variables and explained 8.1% (P = 0.0001) of variance in lithium response. A priori genomic stratification improved non-linear model performance to 13.7% (P = 0.0001) and improved the binary classification of lithium response. This model stratified patients based on their meta-polygenic loadings for major depressive disorder and schizophrenia and was then trained using clinical data.Using PRS to first stratify patients genetically and then train machine-learning models with clinical predictors led to large improvements in lithium response prediction. When used with other PRS and biological markers in the future this approach may help inform which patients are most likely to respond to lithium treatment.

Since more than 3 decades, schizophrenia (SZ) has been regarded as a neurodevelopmental disorder. The neurodevelopmental hypothesis proposes that SZ is associated with genetic and environmental risk factors, which influence connectivity in neuronal circuits during vulnerable developmental periods. We carried out a non-systematic review of genetic/environmental factors that increase SZ risk in light of its neurodevelopmental hypothesis. We also reviewed the potential impact of SZ-related environmental and genetic risk factors on grey and white matter pathology and brain function based on magnetic resonance imaging and post-mortem studies. Finally, we reviewed studies that have used patient-derived neuronal models to gain knowledge of the role of genetic and environmental factors in early developmental stages. Taken together, these studies indicate that a variety of environmental factors may interact with genetic risk factors during the pre- or postnatal period and/or during adolescence to induce symptoms of SZ in early adulthood. These risk factors induce disturbances of macro- and microconnectivity in brain regions involving the prefrontal, temporal and parietal cortices and the hippocampus. On the molecular and cellular level, a disturbed synaptic plasticity, loss of oligodendrocytes and impaired myelination have been shown in brain regions of SZ patients. These cellular/histological phenotypes are related to environmental risk factors such as obstetric complications, maternal infections and childhood trauma and genetic risk factors identified in recent genome-wide association studies. SZ-related genetic risk may contribute to active processes interfering with synaptic plasticity in the adult brain. Advances in stem cell technologies are providing promising mechanistic insights into how SZ risk factors impact the developing brain. Further research is needed to understand the timing of the different complex biological processes taking place as a result of the interplay between genetic and environmental factors.

Lithium is an effective mood stabilizer in bipolar disorder (BD). There is, however, high variability in treatment response to lithium and only 20–30% of individuals with BD are excellent responders. This subgroup has been shown to have specific phenotypic characteristics, and family studies have implicated genetics as an important factor. However, candidate gene studies did not find evidence for major effect genes. Genome-wide association studies (GWAS) have emphasized that lithium response is a polygenic trait. GWAS based on larger sample sizes and non-European ancestries are likely to shed light on the genomic architecture of this trait. Furthermore, induced pluripotent stem cells, transcriptomics, epigenetics, the integration of multiple omics data, and their combination with advanced machine learning techniques hold promise for the understanding of the complex biological underpinnings of lithium treatment response.

The ongoing developments of psychiatric classification systems have largely improved reliability of diagnosis, including that of schizophrenia. However, with an unknown pathophysiology and lacking biomarkers, its validity still remains low, requiring further advancements. Research has helped establish multiple sclerosis (MS) as the central nervous system (CNS) disorder with an established pathophysiology, defined biomarkers and therefore good validity and significantly improved treatment options. Before proposing next steps in research that aim to improve the diagnostic process of schizophrenia, it is imperative to recognize its clinical heterogeneity. Indeed, individuals with schizophrenia show high interindividual variability in terms of symptomatic manifestation, response to treatment, course of illness and functional outcomes. There is also a multiplicity of risk factors that contribute to the development of schizophrenia. Moreover, accumulating evidence indicates that several dimensions of psychopathology and risk factors cross current diagnostic categorizations. Schizophrenia shares a number of similarities with MS, which is a demyelinating disease of the CNS. These similarities appear in the context of age of onset, geographical distribution, involvement of immune-inflammatory processes, neurocognitive impairment and various trajectories of illness course. This article provides a critical appraisal of diagnostic process in schizophrenia, taking into consideration advancements that have been made in the diagnosis and management of MS. Based on the comparison between the two disorders, key directions for studies that aim to improve diagnostic process in schizophrenia are formulated. All of them converge on the necessity to deconstruct the psychosis spectrum and adopt dimensional approaches with deep phenotyping to refine current diagnostic boundaries.

Research Article25 July 2017Open Access Source DataTransparent process Spironolactone is an antagonist of NRG1-ERBB4 signaling and schizophrenia-relevant endophenotypes in mice Michael C Wehr Corresponding Author Michael C Wehr [email protected] orcid.org/0000-0003-1770-8323 Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Wilko Hinrichs Wilko Hinrichs Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Magdalena M Brzózka Magdalena M Brzózka Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Tilmann Unterbarnscheidt Tilmann Unterbarnscheidt Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Cellular Neurophysiology, Center of Physiology, Hannover Medical School, Hannover, Germany Search for more papers by this author Alexander Herholt Alexander Herholt Systasy Bioscience GmbH, Munich, Germany Search for more papers by this author Jan P Wintgens Jan P Wintgens Systasy Bioscience GmbH, Munich, Germany Search for more papers by this author Sergi Papiol Sergi Papiol Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Institute of Psychiatric Phenomics and Genomics (IPPG), Medical Center of the University of Munich, Munich, Germany Search for more papers by this author Maria Clara Soto-Bernardini Maria Clara Soto-Bernardini Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Mykola Kravchenko Mykola Kravchenko Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany Search for more papers by this author Mingyue Zhang Mingyue Zhang Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany Search for more papers by this author Klaus-Armin Nave Klaus-Armin Nave Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Sven P Wichert Sven P Wichert Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Peter Falkai Peter Falkai Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Weiqi Zhang Weiqi Zhang Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany Search for more papers by this author Markus H Schwab Markus H Schwab Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Cellular Neurophysiology, Center of Physiology, Hannover Medical School, Hannover, Germany Center for Systems Neuroscience (ZSN), Hanover, Germany Search for more papers by this author Moritz J Rossner Corresponding Author Moritz J Rossner [email protected] orcid.org/0000-0002-0667-3420 Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Michael C Wehr Corresponding Author Michael C Wehr [email protected] orcid.org/0000-0003-1770-8323 Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Wilko Hinrichs Wilko Hinrichs Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Magdalena M Brzózka Magdalena M Brzózka Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Tilmann Unterbarnscheidt Tilmann Unterbarnscheidt Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Cellular Neurophysiology, Center of Physiology, Hannover Medical School, Hannover, Germany Search for more papers by this author Alexander Herholt Alexander Herholt Systasy Bioscience GmbH, Munich, Germany Search for more papers by this author Jan P Wintgens Jan P Wintgens Systasy Bioscience GmbH, Munich, Germany Search for more papers by this author Sergi Papiol Sergi Papiol Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Institute of Psychiatric Phenomics and Genomics (IPPG), Medical Center of the University of Munich, Munich, Germany Search for more papers by this author Maria Clara Soto-Bernardini Maria Clara Soto-Bernardini Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Mykola Kravchenko Mykola Kravchenko Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany Search for more papers by this author Mingyue Zhang Mingyue Zhang Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany Search for more papers by this author Klaus-Armin Nave Klaus-Armin Nave Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Sven P Wichert Sven P Wichert Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Peter Falkai Peter Falkai Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Search for more papers by this author Weiqi Zhang Weiqi Zhang Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany Search for more papers by this author Markus H Schwab Markus H Schwab Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Cellular Neurophysiology, Center of Physiology, Hannover Medical School, Hannover, Germany Center for Systems Neuroscience (ZSN), Hanover, Germany Search for more papers by this author Moritz J Rossner Corresponding Author Moritz J Rossner [email protected] orcid.org/0000-0002-0667-3420 Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany Search for more papers by this author Author Information Michael C Wehr *,1,‡, Wilko Hinrichs2,‡, Magdalena M Brzózka1, Tilmann Unterbarnscheidt2,3, Alexander Herholt4, Jan P Wintgens4, Sergi Papiol1,5, Maria Clara Soto-Bernardini2, Mykola Kravchenko6, Mingyue Zhang6, Klaus-Armin Nave2, Sven P Wichert1, Peter Falkai1, Weiqi Zhang6, Markus H Schwab2,3,7 and Moritz J Rossner *,1,2 1Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilian University of Munich, Munich, Germany 2Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany 3Cellular Neurophysiology, Center of Physiology, Hannover Medical School, Hannover, Germany 4Systasy Bioscience GmbH, Munich, Germany 5Institute of Psychiatric Phenomics and Genomics (IPPG), Medical Center of the University of Munich, Munich, Germany 6Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Münster, Germany 7Center for Systems Neuroscience (ZSN), Hanover, Germany ‡These authors contributed equally to this work *Corresponding author. Tel: +49 89 4400 53275; Fax: +49 89 4400 55853; E-mail: [email protected] *Corresponding author. Tel: +49 89 4400 55891; Fax: +49 89 4400 55853; E-mail: [email protected] EMBO Mol Med (2017)9:1448-1462https://doi.org/10.15252/emmm.201707691 PDFDownload PDF of article text and main figures. Peer ReviewDownload a summary of the editorial decision process including editorial decision letters, reviewer comments and author responses to feedback. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info Abstract Enhanced NRG1-ERBB4 signaling is a risk pathway in schizophrenia, and corresponding mouse models display several endophenotypes of the disease. Nonetheless, pathway-directed treatment strategies with clinically applicable compounds have not been identified. Here, we applied a cell-based assay using the split TEV technology to screen a library of clinically applicable compounds to identify modulators of NRG1-ERBB4 signaling for repurposing. We recovered spironolactone, known as antagonist of corticosteroids, as an inhibitor of the ERBB4 receptor and tested it in pharmacological and biochemical assays to assess secondary compound actions. Transgenic mice overexpressing Nrg1 type III display cortical Erbb4 hyperphosphorylation, a condition observed in postmortem brains from schizophrenia patients. Spironolactone treatment reverted hyperphosphorylation of activated Erbb4 in these mice. In behavioral tests, spironolactone treatment of Nrg1 type III transgenic mice ameliorated schizophrenia-relevant behavioral endophenotypes, such as reduced sensorimotor gating, hyperactivity, and impaired working memory. Moreover, spironolactone increases spontaneous inhibitory postsynaptic currents in cortical slices supporting an ERBB4-mediated mode-of-action. Our findings suggest that spironolactone, a clinically safe drug, provides an opportunity for new treatment options for schizophrenia. Synopsis Increased levels of Nrg1-ERBB4 signaling are associated with schizophrenia and corresponding mouse models display endophenotypes of the disease. Spironolactone was recovered from a drug repurposing screen to inhibit Nrg1-ERBB4 signaling and improved schizophrenia-relevant phenotypes in Nrg1-transgenic mice. A NRG1-ERBB4 pathway-selective cell-based co-culture assay using the split TEV technique was developed to screen for chemical modulators of Nrg1-ERBB4 signaling. The NIH clinical collection of approved drugs was screened for repurposing these drugs. The mineralo-corticoid antagonist spironolactone was identified as ERBB4 inhibitor and decreases phospho-ERBB4 levels both in cell culture and in vivo. Chronic spironolactone treatment improved aspects of cognitive and positive symptoms of schizophrenia-relevant phenotypes in a Nrg1-transgenic mouse model. Introduction Schizophrenia (SZ) is as severely debilitating neuropsychiatric disorder characterized by positive symptoms, that is, hallucinations and delusions, negative symptoms, that is, lack of motivation, and cognitive symptoms (Insel, 2010). Positive symptoms can frequently be ameliorated by treatment with dopamine receptor antagonists, but efficient treatment options for negative and cognitive symptoms are not available (Goff et al, 2011). Thus, there is a strong clinical need to develop and explore more target-directed therapies for SZ (Nestler & Hyman, 2010). Repurposing of existing drugs principally offers a fast track to the clinic and has been demanded for SZ (Insel, 2012; Lencz & Malhotra, 2015), also because many pharma companies withdrew from research on severe mental disorders (Margraf & Schneider, 2016). Genetic association studies have identified NRG1 and its cognate receptor ERBB4 as SZ risk genes, and altered NRG-ERBB4 signaling has been associated with positive, negative, and cognitive symptoms (Stefansson et al, 2002; Harrison & Law, 2006; Li et al, 2006; Nicodemus et al, 2006). Several postmortem studies revealed increased expression of NRG1 in SZ patients (Hashimoto et al, 2004; Law et al, 2006; Weickert et al, 2012). Elevated expression of the ERBB4-JM-a-CYT-1 variant carrying a PI3K-recruitment domain has also been detected in SZ (Silberberg et al, 2006; Law et al, 2007, 2012). Moreover, ERBB4 was found to be hyperphosphorylated in postmortem brains from SZ patients (Hahn et al, 2006), suggesting that NRG1-ERBB4 hyperstimulation might represent a component of SZ pathophysiology. In agreement, transgenic mice with increased Nrg1 expression display SZ-relevant behavioral deficits, including hyperactivity, impaired sensorimotor gating, decreased social interaction, and reduced cognitive functions (Deakin et al, 2009, 2012; Kato et al, 2010). In particular, transgenic mice with neuronal overexpression of the membrane-bound cysteine-rich-domain (CRD) type III isoform of Nrg1 (Nrg1-tg) display chronic ErbB4 hyperphosphorylation in the cortex, which is associated with a broad spectrum of SZ-relevant endophenotypes, including dysbalanced excitatory and inhibitory neurotransmission, altered spine growth, and impaired sensorimotor gating (Agarwal et al, 2014). Moreover, it has been shown recently that endophenotypes associated with elevated Nrg1 expression are reversible in adult animals, which strongly supports the assumption that the NRG1/ERBB4 signaling system provides a valid target for pharmacological interventions (Yin et al, 2013; Luo et al, 2014). It thus appears plausible that compounds, which can re-balance the activity of the NRG1-ERBB4 signaling pathway, could represent candidates for the therapeutic treatment of schizophrenia beyond positive symptoms. In this study, we have first developed a co-culture assay system compatible with high-throughput-screening (HTS) utilizing the split TEV technology (Wehr et al, 2006, 2008). We then used this assay to screen a library of clinically approved drugs in a repurposing approach to uncover new potential target specificities (Wang & Zhang, 2013), which resulted in the identification and validation of spironolactone as an inhibitor of ERBB4. Finally, we can show that spironolactone decreases phosphorylation levels of ERBB4 in vitro and in vivo and leads to an altered balance of excitation/inhibition of cortical projection neurons. Chronic spironolactone treatment ameliorates hyperactivity and reverses sensorimotor gating and working memory deficits in Nrg1-tg mice. Thus, spironolactone alleviates novel aspects of SZ-relevant symptoms in this mouse model of increased NRG1-ERBB4 signaling. Results A split TEV-based co-culture assay to screen for modulators of NRG1-ERBB4 signaling Screening for modulators of NRG1-ERBB4 signaling in cell culture requires an adequate setup reflecting endogenous signaling mechanisms. According to a current model, NRG1 ligands reside in presynaptic terminals of principle pyramidal neurons, whereas ERBB4 receptors are mainly expressed at the postsynaptic density of dendrites in inhibitory interneurons (Rico & Marín, 2011). Based on this ligand-receptor configuration, NRG1 mediates juxtacrine and paracrine signaling to ERBB4. We established a cellular HTS-compatible co-culture assay, in which NRG1 was expressed in the signal-sending cell population A, whereas ERBB4 was expressed in the signal-receiving cell population B (Fig 1A). Initially, we used the full-length NRG1 type I β1a isoform that undergoes proteolytic cleavage resulting in the release of the extracellular domain, which contains the biologically active EGF-like domain (EGFld), into the extracellular space (Hu et al, 2006; Willem et al, 2006). Therefore, NRG1 type I β1a can elicit juxtacrine (non-cleaved form) and paracrine (cleaved form) stimuli. To screen for approved small compounds that could modulate NRG1-ERBB4 signaling, we combined this co-culture assay with the split TEV protein–protein interaction technique to monitor ERBB4 activation through induced PI3K adaptor recruitment by the human ERBB4-JMa-Cyt1 variant (Fig 1A). Figure 1. A co-culture assay based on the split TEV technique for monitoring NRG1-ERBB4 signaling activity The ERBB4-PIK3R1 split TEV assay monitors NRG1-ERBB4 signaling in PC12 cells. The Nrg1 ligand (green) is stably expressed in the signal-sending cell population A. The signal-receiving cell population B (or split TEV assay cells) is transfected with plasmids encoding the assay components ERBB4 (red) fused to NTEV-tevS-GV (ERBB4-NTEV-tevS-GV), the adapter molecule PIK3R1 (purple, the regulatory subunit alpha of the PI3K) fused to CTEV (PIK3R1-CTEV), and a UAS-driven firefly luciferase reporter (Fluc). Upon Nrg1 binding to the extracellular domain of ERBB4 (1), ERBB4-NTEV-tevS-GV dimerizes and cross-phosphorylates itself (2). PIK3R1-CTEV binds to the phosphorylated ERBB4 receptor leading to the functional reconstitution of TEV protease activity and the concomitant release of the artificial co-transcriptional activator Gal4-VP16 (GV) through proteolytic cleavage at a TEV protease cleavage site (tevS) (3). In turn, released GV translocates to the nucleus and binds to UAS sequences (open box) to activate the transcription of a firefly reporter gene (4). Dose–response assay using increasing numbers of Nrg1 type I β1a-expressing PC12 cells. For each 96-well, 40,000 split TEV assay cells were co-plated with increasing numbers of Nrg1-expressing cells and incubated for 24 h. Half-maximal activation is reached at 5,000 Nrg1-expressing cells. The Z’ factor is 0.5 indicating a large separation band for this assay. Adding 10 ng/ml EGFld resulted in a twofold activation. Per 96-well, 40,000 split TEV assay cells were co-plated with empty PC12 cells (no Nrg1 expression), 10,000 Nrg1-expressing cells, and 10,000 Nrg1-expressing cells plus 10 ng/ml EGFld. Arrows indicate measuring window of activation (blue arrow) and inhibition (red arrow) relative to baseline activity. Lapatinib antagonizes ERBB4-PIK3R1 signaling in a dose-dependent manner. Per 96-well, 40,000 split TEV assay cells were incubated with increasing amounts of lapatinib, followed by co-plating 10,000 Nrg1 type I β1a-expressing cells. The inset depicts the IC50 value in μM. Data information: After compound/stimulus addition, each assay was incubated for 24 h. RLU, relative luciferase units; Fluc, firefly luciferase activity (black line); Rluc, Renilla luciferase activity (gray line); n = 6; data are shown as mean, and error bars represent SEM. Download figure Download PowerPoint The functionality and robustness of the co-culture assay was investigated by co-plating increasing numbers of PC12 cells carrying a stably integrated mouse Nrg1 type I β1a expression cassette (Nrg1 cells, Fig EV1A for stable Nrg1 expression) with ERBB4-PIK3R1-expressing PC12 cells (split TEV assay cells). Co-culture conditions were verified using two PC12 cell populations expressing either EYFP or ECFP (Fig EV1B). A dose–response analysis showed that the assay reached a plateau of activation when 10,000 Nrg1-expressing cells were co-plated with 40,000 split TEV assay cells, with half-maximal activation at 5,000 cells (Fig 1B). Calculation of the Z’ factor, a measure of HTS applicability and quality (Zhang et al, 1999), resulted in a value of 0.5 indicating a large separation band at screening conditions. Importantly, addition of the soluble EGFld resulted in a twofold increase of ERBB4 activation compared with Nrg1 cells alone, implying that ERBB4 activation in the co-culture assay can be decreased and increased by potential NRG1-ERBB4 inhibitors and activators, respectively (Fig 1C). In addition, dose–response assays using ERBB4-PIK3R1 split TEV assay cells only and soluble EGFld as stimulus (single-culture assay) showed stable and reproducible dose–responses that also qualified for HTS, with Z’ factors between 0.56 and 0.68 for three independent assays (Fig EV1C). The specificity of the NRG1-ERBB4 co-culture assay was validated in dose–response assays using established ERBB4 inhibitors, such as lapatinib (IC50 value at 2.61 μM, co-culture assay, Fig 1D; 0.45 μM, single-culture assay, Fig EV1D) and CI-1033 (IC50 value at 0.01 μM, co-culture assay, Fig EV1E; 0.004 μM, single-culture assay, Fig EV1F). Taken together, these data indicate that the split TEV-based co-culture assay provides a robust platform to screen for modulators of NRG1-ERBB4 signaling. Click here to expand this figure. Figure EV1. A co-culture assay based on the split TEV technique to monitor NRG1-ERBB4 signaling activity A. PC12 cell lines stably expressing mouse Nrg1 type I β1a and Nrg1 type III β1a. PC12 cells were stably transfected with a plasmid encoding Nrg1 type I β1a or type III β1a, and Nrg1 expression was verified by Western blot analysis using an Nrg1 antibody that detects the β1a C-terminus. B. Co-culturing two populations of PC12 cells. Cell population A was transfected with a nuclear localized EYFP (EYFPnuc), and cell population B was transfected with ECFP. Following to an initial expression of 24 h, cells were mixed and imaged 24 h later. Scale bar, 100 μm. C. ERBB4-PIK3R1 dose–response assay using EGFld as stimulus. Three independent experiments using the ERBB4-PIK3R1/EGFld assay are shown. The EC50 value for this assay is at 1 ng/ml EGFld. The inset depicts the Z’ factors for each individual assay. D. Lapatinib antagonizes ERBB4-PIK3R1 signaling in a dose-dependent manner. Per 96-well, 40,000 split TEV assay cells were incubated with increasing amounts of lapatinib, followed by a stimulation using 10 ng/ml EGFld. E, F. CI-1033 antagonizes ERBB4-PIK3R1 signaling in a dose-dependent manner. Per 96-well, 40,000 split TEV assay cells were incubated with increasing amounts of CI-1033, followed by either co-plating 10,000 Nrg1-expressing cells (E) or stimulation with 10 ng/ml EGFld (F). Data information: Fluc, firefly luciferase activity (black lines); Rluc, Renilla luciferase activity (gray lines, indicating toxicity levels). Data are shown as mean, and error bars represent SEM, n = 6. The insets depict IC50 values in μM. Source data are available online for this figure. Download figure Download PowerPoint Screening the NIH clinical compound collection recovers spironolactone as ERBB4 receptor antagonist We used the split TEV-based NRG1-ERBB4-PIK3R1 co-culture assay to screen two sets of the NIH Clinical Collection (NIH-NCC) containing 727 FDA-approved drugs in total (Fig 2A). From this screen, we selected a primary hit list of candidates that were at least three standard deviations away from the mean (Fig 2B for NIH-NCC set 1; Fig EV2A for NIH-NCC set 2; Dataset EV1). These candidates were then subjected to individual re-screening to eliminate off-target effects, such as toxicity and interference with assay tools, and 18 substances met these criteria and were selected for the final hit list (Appendix Fig S1 for a flowchart of all screening and validation steps; see Appendix Table S1 for final hit list). Spironolactone, a mineralocorticoid receptor (MR) antagonist formerly used as a diuretic and to treat high blood pressure (Gaddam et al, 2010), was recovered as top antagonist candidate (Fig 2B). In a dose–response co-culture assay using Nrg1 type I β1a, spironolactone displayed an IC50 value of 1.0 μM, and marginal toxic effects at higher concentrations, as indicated by reduced Renilla luciferase readings (Fig 2C). ERBB4-specific effects were confirmed by dose–response control assays, which showed absence of spironolactone effects on assay components (Fig EV2B and C). Figure 2. Spironolactone is the primary candidate recovered from the co-culture screen A. Flow chart of the compound screen. PC12 cells (population A) were transfected in solution with the split TEV assay plasmids ERBB4-NTEV-tevS-GV and PIK3R1-CTEV and incubated for 2 h before seeded onto 96-well plates. Population A cells were allowed to express the plasmids for 24 h. Compounds were added in a concentration of 10 μM, followed by seeding the Nrg1-expressing PC12 cells (population B) half an hour later. After 24 h of compound incubation, cells were lysed and subjected to a dual luciferase assay. The screening data were analyzed using the cellHTS2 package in R Bioconductor. B. Graphic visualization of the primary screen data of the NIH-NCC library set 1. All counts (320 compounds and 64 controls) from the Nrg1-ERBB4-PIK3R1 split TEV compound screen were plotted against the Z-score using the Mondrian program, with pathway activators displaying high values and inhibitors low values. For the secondary analysis, we selected all candidates that were at least three standard deviations away from the mean. EGFld-positive and lapatinib/CI-1033-negative controls are shown in red. C, D. Spironolactone antagonizes Nrg1-ERBB4-PIK3R1 signaling. In dose–response assays using ERBB4-NTEV-tevS-GV and PIK3R1-CTEV plasmids transfected into PC12 cells, spironolactone was administered at increasing concentrations before seeding (C) Nrg1 type I- or (D) Nrg1 type III-expressing PC12 cells. E. Spironolactone inhibits ERBB4 receptor dimerization. Dose-dependent dimerization of the ERBB4 receptor was analyzed using a split TEV assay encompassing ERBB4-NTEV-tevS-GV and ERBB4-CTEV plasmids transfected into PC12 cells. 10 ng/ml EGFld was applied as Nrg1 stimulus. Data information: Fluc, firefly luciferase activity (black lines); Rluc, Renilla luciferase activity (gray lines, indicating toxicity levels); n = 6; data are shown as mean, and error bars represent SEM. The insets depict IC50 values in μM. Download figure Download PowerPoint Click here to expand this figure. Figure EV2. Spironolactone is the top candidate recovered from the co-culture screen A. Graphic visualization of the primary screen data of the NIH-NCC library, set 2. All counts (407 compounds and 96 controls) from the Nrg1-ERBB4-PIK3R1 split TEV compound screen were plotted against the z-score using Mondrian, with pathway activators displaying high values and inhibitors low values. For the secondary analysis, we selected all candidates that were at least three standard deviations away from the mean. EGFld-positive and lapatinib/CI-1033-negative controls are shown in red. B, C. Spironolactone does not affect activities of control assays. Neither the activity of the GAL4/UAS system (B) nor the activity of the TEV protease (C) was affected in spironolactone dose-dependent assays. For the GAL4/UAS assay, GAL4-VP16 (GV) and 10×UAS firefly luciferase (10×UAS-Fluc) plasmids were transfected into PC12 cells. For TEV protease activity assays, a transmembrane-localized TEV protease (TM-TEV) was expressed in PC12 cells with a transmembrane-localized and TEV-cleavable GV (TM-tevS-GV) and the 10×UAS-Fluc reporter. 10 ng/μl EGFld was applied as Nrg1 stimulus. In both control assays, the assay activity (firefly luciferase, black lines) was similar to the toxicity levels (gray lines). Data are shown as mean, a nd error bars represent SEM, n = 6. The insets depict IC50 values in μM. Download figure Download PowerPoint Importantly, spironolactone also inhibited ERBB4 activity (IC50 value of 1.1 μM) in a co-culture assay using the membrane-bound CRD containing type III isoform of Nrg1, the major NRG1 isoform in the brain, which is implicated in juxtacrine signaling (Fig 2D). Thus, spironolactone modulates ERBB4 activity downstream from both paracrine and juxtacrine NRG1 signaling. Further, spironolactone acts at a proximal step of ERBB4 receptor activation upstream of tyrosine phosphorylation and adapter recruitment as ERBB4 dimerization stimulated by EGFld was efficiently inhibited (IC50 value of 1.1 μM) in a single-culture assay (Fig 2E). Finally, we used an ERBB4 variant that lacks the intracellular domain, and thus is signaling incompetent, but expresses at the cell cortex and dimerizes upon EGFld stimulation (Fig EV3A and B). Notably, spironolactone inhibits dimerization of full-length ERBB4, but not of C-terminally truncated ERBB4 (Fig EV3C). Click here to expand this figure. Figure EV3. Truncated ERBB4 dimers are not inhibited by spironolactone Full-length and truncated ERBB4 split TEV fusions localize to the cell membrane. PC12 cells were transfected with a full-length human ERBB4 split TEV fusion (ERBB4-NTEV-tevS-GV-2HA) (left panels) or a truncated human ERBB4 split TEV fusion (ERBB4_1–685_NTEV-tevS-GV-2HA) that covers residues 1–685 and contains the transmembrane domain but lacks the intracellular domain (right panels). Cells were allowed to express the fusion proteins for 24 h, fixed, and stained for the double HA (2HA) tag. Arrowheads indicate expression of full-length and truncated ERBB4 at the membrane. Scale bars, 5 μm. Both full-length and truncated ERBB4 dimerize in split TEV assays when stimulated with extracellular EGFld. PC12 cells were transfected with split TEV pairs of ERBB4-NTEV-tevS-GV/-CTEV and ERBB4_1–685_NTEV-tevS-GV/-CTEV, starved overnight, stimulated with EGFld (10 ng/ml) or mock-stimulated (unstim), incubated for 20 h, lysed, and subjected to a luciferase assay. Fluc, firefly luciferase activity. Spironolactone-mediated inhibition of the ERBB4 dimerization requires the intracellular domain. Truncated ERBB4 receptor molecules (amino acids 1–685) were fused to N- and CTEV moieties, transfected into PC12 cells and assayed in a spironolactone dose-dependent assay in the presence of 10 ng/ml EGFld using the split TEV technique. Spironolactone had no inhibitory effect, as the assay activity (Fluc, firefly luciferase, black line) was comparable to the toxicity levels (Rluc, Renilla luciferase, gray line). The inset depicts the IC50 value in μM. Spironolactone reduces ERBB4 levels. PC12 cells were transfected with the split TEV assay plasmid ERBB4-NTEV-tevS-GV (where indicated), stimulated with 10 ng/ml EGFld, 10 μM lapatinib, and 10 μM spironolactone for 1 h as indicat

Childhood trauma has been associated with a heightened risk for presenting clinical and non-clinical psychopathology in adulthood. Genes related with the stress response, such as the FK506 binding protein 51 (FKBP5), are plausible candidates moderating the effects of childhood trauma on the emergence of such symptoms later on. The present study aimed to explore the moderating role of FKBP5 genetic variability on the association of different types of childhood trauma with subclinical psychosis, depression and anxiety in a non-clinical sample. Schizotypy, psychotic-like experiences, depression and anxiety symptoms and childhood trauma were assessed in 808 young adults. Two FKBP5 haplotypic blocks were detected: block 1 (rs3800373 − rs9296158 − rs1360780) and block 2 (rs9470080 − rs4713916). Subjects were classified in two groups according to whether they carried or not the risk haplotype previously described in the literature (block 1: CAT and block 2: TA). Linear regression analyses were used to study (i) the main effects of childhood trauma and FKBP5 haplotype blocks and (ii) their interaction effects on the mentioned forms of psychopathology. All childhood trauma scales, except sexual abuse, were associated with schizotypy, psychotic-like experiences, depression and anxiety symptoms. None of the analysed symptoms was associated with the main effects of FKBP5 genetic variability. However an interaction effect between block 1 and physical abuse was observed on anxiety, with lower scores in CAT carriers. This effect was driven by SNP 1 and 2. Moreover, an interaction effect between block 2 and physical abuse was identified on the variables tapping depressive and anxiety symptoms. Specifically, non-TA carrier subjects who were exposed to physical abuse were found to be at higher risk for depressive and anxiety symptoms. These effects were driven by SNP 5. No interaction effect was observed for the other variables. Our data suggest that exposure to childhood physical abuse may increase the risk for sub-clinical depressive and anxiety symptoms depending on FKBP5 genetic variability. Further research is needed to better elucidate the role of FKBP5 on mental health in clinical and non-clinical cohorts.

Postmortem studies in patients with schizophrenia (SCZ) have revealed deficits in myelination, abnormalities in myelin gene expression and altered numbers of oligodendrocytes in the brain. However, gaining mechanistic insight into oligodendrocyte (OL) dysfunction and its contribution to SCZ has been challenging because of technical hurdles. The advent of individual patient-derived human-induced pluripotent stem cells (hiPSCs), combined with the generation of in principle any neuronal and glial cell type, including OLs and oligodendrocyte precursor cells (OPCs), holds great potential for understanding the molecular basis of the aetiopathogenesis of genetically complex psychiatric diseases such as SCZ and could pave the way towards personalized medicine. The development of neuronal and glial co-culture systems now appears to enable the in vitro study of SCZ-relevant neurobiological endophenotypes, including OL dysfunction and myelination, with unprecedented construct validity. Nonetheless, the meaningful stratification of patients before the subsequent functional analyses of patient-derived cell systems still represents an important bottleneck. Here, to improve the predictive power of ex vivo disease modelling we propose using hiPSC technology to focus on representatives of patient subgroups stratified for genomic and/or phenomic features and neurobiological cell systems. Therefore, this review will outline the evidence for the involvement of OPCs/OLs in SCZ in the context of their proposed functions, including myelination and axon support, the implications for hiPSC-based cellular disease modelling and potential strategies for patient selection.

Magnetic resonance imaging (MRI) studies have shown some morphological and volumetric peculiarities in brains of schizophrenic patients. The authors explored the influence of genetic polymorphisms at interleukin-1β (IL-1B) and interleukin-1 receptor antagonist (IL-1RN) genes on these abnormalities. Hippocampus, lateral ventricles, and dorsolateral prefrontal cortex gray matter volumes were measured in a sample of 23 DSM-IV diagnosed schizophrenic patients of Spanish origin using MRI scans; MRI data were adjusted for age and brain volume using regression parameters from a healthy control group (n = 45). IL-1B and IL-1RN genes, involved in neurodevelopment and neurodegenerative processes, were analyzed in the patient sample. Patients carrying VNTR-allele*2 of IL-1RN gene showed a significant enlargement of both left (P = 0.002) and right (P = 0.01) ventricles. Sex and illness duration were controlled for in the analyses. Our results, though preliminary, suggest that IL-1RN gene might contribute to the ventricular volumetric changes observed in schizophrenic patients.

Stress plays a major role in the development of comorbid alcohol use disorder (AUD). In turn, AUD worsens the outcome of psychiatric patients with respect to global disease severity, social situation, and socioeconomic burden. Prediction of persons at risk for AUD is crucial for future preventive and therapeutic strategies.To investigate whether genetic variants of the corticotropin-releasing factor system or their interaction influence the risk of developing AUD in chronic disease populations.Genotype analysis comprising selected single-nucleotide polymorphisms within the CRHR1 and CRHBP genes in patients with schizophrenia and in a nonschizophrenic psychiatric disease control sample should allow the extraction of predictors of comorbid AUD. Gene expression (messenger RNA) analysis in peripheral blood mononuclear cells was performed to gain the first mechanistic insight.An ideal setup for this study was the Göttingen Research Association for Schizophrenia Data Collection of schizophrenic patients, specifically intended to enable association of genetic information with quantifiable phenotypes in a phenotype-based genetic association study. Patients A total of 1037 schizophrenic patients (Göttingen Research Association for Schizophrenia sample), 80 nonschizophrenic psychiatric disease controls as a small replicate sample, and a case-control study including 1141 healthy subjects.Association of CRHR1 and CRHBP genotypes with the following: (1) AUD; (2) a newly developed alcoholism severity score comprising 5 AUD-relevant variables; and (3) quantitative CRHR1 and CRHBP messenger RNA expression.An interaction of CRHR1 rs110402 and CRHBP rs3811939 predicts high risk of comorbid AUD in schizophrenic patients (odds ratio = 2.27; 95% confidence interval, 1.56-3.30; P < .001) as well as psychiatric disease controls (odds ratio = 4.02; 95% confidence interval, 0.95-17.05; P = .06) and leads to the highest CRHR1/CRHBP messenger RNA ratio (P = .02; dysbalanced stress axis).The high predictive value of a genetic interaction within the stress axis for the risk of comorbid AUD may be used for novel preventive and individualized therapeutic approaches.

Anxiety disorders and substance abuse, including benzodiazepine use disorder, frequently occur together. Unfortunately, treatment of anxiety disorders still includes benzodiazepines, and patients with an existing comorbid benzodiazepine use disorder or a genetic susceptibility for benzodiazepine use disorder may be at risk of adverse treatment outcomes. The identification of genetic predictors for anxiety disorders, and especially for benzodiazepine use disorder, could aid the selection of the best treatment option and improve clinical outcomes. The brain-specific angiogenesis inhibitor I-associated protein 3 (Baiap3) is a member of the mammalian uncoordinated 13 (Munc13) protein family of synaptic regulators of neurotransmitter exocytosis, with a striking expression pattern in amygdalae, hypothalamus and periaqueductal gray. Deletion of Baiap3 in mice leads to enhanced seizure propensity and increased anxiety, with the latter being more pronounced in female than in male animals. We hypothesized that genetic variation in human BAIAP3 may also be associated with anxiety. By using a phenotype-based genetic association study, we identified two human BAIAP3 single-nucleotide polymorphism risk genotypes (AA for rs2235632, TT for rs1132358) that show a significant association with anxiety in women and, surprisingly, with benzodiazepine abuse in men. Returning to mice, we found that male, but not female, Baiap3 knockout (KO) mice develop tolerance to diazepam more quickly than control animals. Analysis of cultured Baiap3 KO hypothalamus slices revealed an increase in basal network activity and an altered response to diazepam withdrawal. Thus, Baiap3/BAIAP3 is gender specifically associated with anxiety and benzodiazepine use disorder, and the analysis of Baiap3/BAIAP3-related functions may help elucidate mechanisms underlying the development of both disorders.

Genetic studies have found that the interleukin-1β gene (IL1B, 2q13) influences the risk for schizophrenia, but the underlying biological mechanisms of the association are still unclear. Investigation of the effects of genetic variability in this gene on brain function could provide more information about its role in the disorder.The present study examined the effects of a functional polymorphism at IL1B gene promoter (-511C/T; rs16944) on brain correlates of working memory performance in schizophrenia. Forty-eight schizophrenia patients and 46 control subjects underwent functional magnetic resonance imaging while performing the n-back task.In the pooled sample, genetic variability at this locus was associated with differential brain activation in a bilateral frontal region including the dorsolateral prefrontal cortex. There was also a significant diagnosis × genotype interaction effect in an overlapping frontal region: the IL1B polymorphism did not affect activation in the control subjects in this area, but the schizophrenia patients who were T carriers showed significantly higher activation than the CC homozygotes.The findings support a role for IL1B variability in the dorsolateral prefrontal cortex dysfunction classically associated with schizophrenia.

There is a paucity of efficacious new compounds to treat neuropsychiatric disorders. We present a novel approach to neuropsychiatric drug discovery based on high-content characterization of druggable signaling network responses at the single-cell level in patient-derived lymphocytes ex vivo. Primary T lymphocytes showed functional responses encompassing neuropsychiatric medications and central nervous system ligands at established (e.g., GSK-3β) and emerging (e.g., CrkL) drug targets. Clinical application of the platform to schizophrenia patients over the course of antipsychotic treatment revealed therapeutic targets within the phospholipase Cγ1-calcium signaling pathway. Compound library screening against the target phenotype identified subsets of L-type calcium channel blockers and corticosteroids as novel therapeutically relevant drug classes with corresponding activity in neuronal cells. The screening results were validated by predicting in vivo efficacy in an independent schizophrenia cohort. The approach has the potential to discern new drug targets and accelerate drug discovery and personalized medicine for neuropsychiatric conditions.

Abstract Cognitive deficits are a core feature of psychiatric disorders like schizophrenia and bipolar disorder. Evidence supports a genome-wide polygenic score (GPS) for educational attainment (GPS EDU ) can be used to explain variability in cognitive performance. We aimed to identify different cognitive domains associated with GPS EDU in a transdiagnostic clinical cohort of chronic psychiatric patients with known cognitive deficits. Bipolar and schizophrenia patients from the PsyCourse cohort ( N = 730; 43% female) were used. Likewise, we tested whether GPSs for schizophrenia (GPS SZ ) and bipolar disorder (GPS BD ) were associated with cognitive outcomes. GPS EDU explained 1.5% of variance in the backward verbal digit span, 1.9% in the number of correctly recalled words of the Verbal Learning and Memory Test, and 1.1% in crystallized intelligence. These effects were robust to the influences of treatment and diagnosis. No significant associations between GPS SZ or GPS BD with cognitive outcomes were found. Furthermore, these risk scores did not confound the effect of GPS EDU on cognitive outcomes. GPS EDU explains a small fraction of cognitive performance in adults with psychiatric disorders, specifically for domains related to linguistic learning and working memory. Investigating such a proxy-phenotype longitudinally, could give intriguing insight into the disease course, highlighting at what time genes play a more influential role on cognitive performance. Better understanding the origin of these deficits might help identify those patients at risk for lower levels of functioning and poor social outcomes. Polygenic estimates may in the future be part of predictive models for more personalized interventions.

Recent evidence suggests that comorbidities between neuropsychiatric conditions and metabolic syndrome may precede and even exacerbate long-term side-effects of psychiatric medication, such as a higher risk of type 2 diabetes and cardiovascular disease, which result in increased mortality. In the present study we compare the expression of key metabolic proteins, including the insulin receptor (CD220), glucose transporter 1 (GLUT1) and fatty acid translocase (CD36), on peripheral blood mononuclear cell subtypes from patients across the neuropsychiatric spectrum, including schizophrenia, bipolar disorder, major depression and autism spectrum conditions (n = 25/condition), relative to typical controls (n = 100). This revealed alterations in the expression of these proteins that were specific to schizophrenia. Further characterization of metabolic alterations in an extended cohort of first-onset antipsychotic drug-naïve schizophrenia patients (n = 58) and controls (n = 63) revealed that the relationship between insulin receptor expression in monocytes and physiological insulin sensitivity was disrupted in schizophrenia and that altered expression of the insulin receptor was associated with whole genome polygenic risk scores for schizophrenia. Finally, longitudinal follow-up of the schizophrenia patients over the course of antipsychotic drug treatment revealed that peripheral metabolic markers predicted changes in psychopathology and the principal side effect of weight gain at clinically relevant time points. These findings suggest that peripheral blood cells can provide an accessible surrogate model for metabolic alterations in schizophrenia and have the potential to stratify subgroups of patients with different clinical outcomes or a greater risk of developing metabolic complications following antipsychotic therapy.

This mendelian randomization analyzes the potential causality between physical activity and schizophrenia.

Introduction According to the World Health Organization, medication adherence is defined as the extent to which a person's behavior corresponds with an agreed recommendation from a healthcare provider. Approximately 50% of patients do not take their medication as prescribed, and non-adherence can contribute to the progress of a disease. For patients suffering from mental diseases non-adherence plays an important role. Various factors have been proposed as contributing to non-adherence, however the literature remains heterogeneous dependent on the analyzed patient subgroups. This study comprehensively evaluates the association of sociodemographic, clinical, personality and quality of life related factors with medication adherence by analyzing data from the PsyCourse study. The PsyCourse study is a large and cross-diagnostic cohort of psychiatric patients from the affective-to-psychotic spectrum. Methods The study sample comprised 1,062 patients from the PsyCourse study with various psychiatric diagnoses (mean [SD] age, 42.82 [12.98] years; 47.4% female). Data were analyzed to identify specific factors associated with medication adherence, and adherence was measured by a self-rating questionnaire. Odds ratios (OR) were estimated by a logistic regression for binary outcomes. Missing data were imputed using multiple imputation. Results The following factors showed the strongest association with medication adherence: never having used illicit drugs (OR, 0.71), number of prescribed antipsychotics (OR, 1.40), the personality trait conscientiousness (OR, 1.26), and the environmental domain of quality of life (OR, 1.09). Conclusion In a large and cross-diagnostic sample, we could show that a higher level of conscientiousness, a higher number of antipsychotic medication, a better quality of life within the environmental domain, and the absence of substance abuse contribute to a better medication adherence independent of the underlying disorder.

To date, besides genome-wide association studies, a variety of other genetic analyses (e.g. polygenic risk scores, whole-exome sequencing and whole-genome sequencing) have been conducted, and a large amount of data has been gathered for investigating the involvement of common, rare and very rare types of DNA sequence variants in bipolar disorder. Also, non-invasive neuroimaging methods can be used to quantify changes in brain structure and function in patients with bipolar disorder.To provide a comprehensive assessment of genetic findings associated with bipolar disorder, based on the evaluation of different genomic approaches and neuroimaging studies.We conducted a PubMed search of all relevant literatures from the beginning to the present, by querying related search strings.ANK3, CACNA1C, SYNE1, ODZ4 and TRANK1 are five genes that have been replicated as key gene candidates in bipolar disorder pathophysiology, through the investigated studies. The percentage of phenotypic variance explained by the identified variants is small (approximately 4.7%). Bipolar disorder polygenic risk scores are associated with other psychiatric phenotypes. The ENIGMA-BD studies show a replicable pattern of lower cortical thickness, altered white matter integrity and smaller subcortical volumes in bipolar disorder.The low amount of explained phenotypic variance highlights the need for further large-scale investigations, especially among non-European populations, to achieve a more complete understanding of the genetic architecture of bipolar disorder and the missing heritability. Combining neuroimaging data with genetic data in large-scale studies might help researchers acquire a better knowledge of the engaged brain regions in bipolar disorder.

Over the last few years, extracellular vesicles (EVs) have received increasing attention as potential non-invasive diagnostic and therapeutic biomarkers for various diseases. The interest in EVs is related to their structure and content, as well as to their changing cargo in response to different stimuli. One of the potential areas of use of EVs as biomarkers is the central nervous system (CNS), in particular the brain, because EVs can cross the blood-brain barrier, exist also in peripheral tissues and have a diverse cargo. Thus, they may represent "liquid biopsies" of the CNS that can reflect brain pathophysiology without the need for invasive surgical procedures. Overall, few studies to date have examined EVs in neuropsychiatric disorders, and the present evidence appears to lack reproducibility. This situation might be due to a variety of technical obstacles related to working with EVs, such as the use of different isolation strategies, which results in non-uniform vesicular and molecular outputs. Multi-omics approaches and improvements in the standardization of isolation procedures will allow highly pure EV fractions to be obtained in which the molecular cargo, particularly microRNAs and proteins, can be identified and accurately quantified. Eventually, these advances will enable researchers to decipher disease-relevant molecular signatures of the brain-derived EVs involved in synaptic plasticity, neuronal development, neuro-immune communication, and other related pathways. This narrative review summarizes the findings of studies on EVs in major psychiatric disorders, particularly in the field of biomarkers, and discusses the respective therapeutic potential of EVs.

Abstract Schizophrenia (SZ) is a complex disorder with a highly polygenic inheritance. It can be conceived as the extreme expression of a continuum of traits that are present in the general population often broadly referred to as schizotypy. However, it is still poorly understood how these traits overlap genetically with the disorder. We investigated whether polygenic risk for SZ is associated with these disorder-related phenotypes (schizotypy, psychotic-like experiences, and subclinical psychopathology) in a sample of 253 non-clinically identified participants. Polygenic risk scores (PRSs) were constructed based on the latest SZ genome-wide association study using the PRS-CS method. Their association with self-report and interview measures of SZ-related traits was tested. No association with either schizotypy or psychotic-like experiences was found. However, we identified a significant association with the Motor Change subscale of the Comprehensive Assessment of At-Risk Mental States (CAARMS) interview. Our results indicate that the genetic overlap of SZ with schizotypy and psychotic-like experiences is less robust than previously hypothesized. The relationship between high PRS for SZ and motor abnormalities could reflect neurodevelopmental processes associated with psychosis proneness and SZ.

Objectives Bipolar disorder (BD) with early disease onset is associated with an unfavorable clinical outcome and constitutes a clinically and biologically homogenous subgroup within the heterogeneous BD spectrum. Previous studies have found an accumulation of early age at onset (AAO) in BD families and have therefore hypothesized that there is a larger genetic contribution to the early‐onset cases than to late onset BD. To investigate the genetic background of this subphenotype, we evaluated whether an increased polygenic burden of BD‐ and schizophrenia (SCZ)‐associated risk variants is associated with an earlier AAO in BD patients. Methods A total of 1995 BD type 1 patients from the Consortium of Lithium Genetics (ConLiGen), PsyCourse and Bonn‐Mannheim samples were genotyped and their BD and SCZ polygenic risk scores (PRSs) were calculated using the summary statistics of the Psychiatric Genomics Consortium as a training data set. AAO was either separated into onset groups of clinical interest (childhood and adolescence [≤18 years] vs adulthood [&gt;18 years]) or considered as a continuous measure. The associations between BD‐ and SCZ‐PRSs and AAO were evaluated with regression models. Results BD‐ and SCZ‐PRSs were not significantly associated with age at disease onset. Results remained the same when analyses were stratified by site of recruitment. Conclusions The current study is the largest conducted so far to investigate the association between the cumulative BD and SCZ polygenic risk and AAO in BD patients. The reported negative results suggest that such a polygenic influence, if there is any, is not large, and highlight the importance of conducting further, larger scale studies to obtain more information on the genetic architecture of this clinically relevant phenotype.

Abstract The transcription factor TCF4 was confirmed in several large genome-wide association studies as one of the most significant schizophrenia (SZ) susceptibility genes. Transgenic mice moderately overexpressing Tcf4 in forebrain ( Tcf4 tg) display deficits in fear memory and sensorimotor gating. As second hit, we exposed Tcf4 tg animals to isolation rearing (IR), chronic social defeat (SD), enriched environment (EE), or handling control (HC) conditions and examined mice with heterozygous deletion of the exon 4 ( Tcf4Ex4δ +/− ) to unravel gene-dosage effects. We applied multivariate statistics for behavioral profiling and demonstrate that IR and SD cause strong cognitive deficits of Tcf4 tg mice, whereas EE masked the genetic vulnerability. We observed enhanced long-term depression in Tcf4 tg mice and enhanced long-term potentiation in Tcf4Ex4δ +/− mice indicating specific gene-dosage effects. Tcf4 tg mice showed higher density of immature spines during development as assessed by STED nanoscopy and proteomic analyses of synaptosomes revealed concurrently increased levels of proteins involved in synaptic function and metabolic pathways. We conclude that environmental stress and Tcf4 misexpression precipitate cognitive deficits in 2-hit mouse models of relevance for schizophrenia.

Little is known about long-term outcomes of the first episode of psychosis (FEP) other than in the symptomatic domain. We hypothesised that cognitive impairment is associated with poorer multi-domain outcomes at a long-term follow-up of FEP patients. We followed-up 172 FEP patients for a mean of 20.3 years. Ten outcome dimensions were assessed (symptomatic, functional and personal recovery, social disadvantage, physical health, suicide attempts, number of episodes, current drug use, chlorpromazine equivalent doses (CPZ), and schizophrenia/schizoaffective disorder final diagnosis). Cognition was assessed at follow-up. Processing speed and verbal memory deficits showed significant associations with poor outcomes on symptomatic, social functioning, social disadvantage, higher number of episodes, and higher CPZ. Significant associations were found between visual memory impairments were significantly associated with low symptomatic and functional recovery, between attentional deficits and a final diagnosis of schizophrenia/schizoaffective disorder, and between social cognition deficits and poor personal recovery.Lower cognitive global scores were significantly associated with all outcome dimensions except for drug abuse and physical status. Using multiple outcome dimensions allowed for the inclusion of the patients' perspective and other commonly neglected outcome measures. Taken together, cognitive impairment in FEP patients is strongly related to poor performance on several outcome dimensions beyond symptomatic remission.

Abstract Hypoactivity of the dorsolateral prefrontal cortex (DLPFC) during cognitive tasks is among the most consistent findings in schizophrenia. The biological factors contributing to this hypofrontality are only partially known. Previous reports have shown the influence of genes mapped to IL‐1 cluster (i) in the risk to develop schizophrenia and (ii) on brain morphological abnormalities in these patients. Moreover, Interleukin‐1β (IL‐1β), encoded by IL‐1B gene (IL‐1 cluster, chromosome 2q13) has a key role in dopaminergic differentiation and dendrite growth in developing cortical neurons. The authors explored the role of a genetic functional polymorphism at IL‐1B gene in relation to DLPFC activity. DLPFC (left and right) metabolic activity was measured in a sample of 19 DSM‐IV diagnosed schizophrenic patients of Spanish origin using a procedure based on MRI/PET image fusion. During PET studies, subjects performed a contingent Continuous Performance Test aiming to activate DLPFC. Functional promoter polymorphism −511 C/T (rs16944) of IL‐1B gene was genotyped in these patients. Those patients who were allele 2 (−511 T) carriers showed a lower metabolic activity in the left DLPFC with respect to patients homozygous for allele 1 (−511 C) (U = 16, z = −2.32, P = 0.02). Our results suggest that hypofrontality reported in some schizophrenic patients might be explained, at least in part, by this functional polymorphism at IL‐1B gene. Genetic variants with influence on brain functionality may account for the neurocognitive heterogeneity observed in schizophrenic patients. © 2007 Wiley‐Liss, Inc.

Abstract Dysbindin‐1 is a relatively ubiquitous protein in the brain which is involved in the modulation of synaptic homeostasis. The dysbindin‐1 gene ( DTNBP1 ) has been associated with schizophrenia and bipolar disorder diagnoses. However, its contribution to the severity of the clinical and neurocognitive expression of these disorders remains controversial. We aimed to explore the association between DTNBP1 and the phenotypes which are more directly linked with the underlying biology, such as age at onset and neurocognitive impairment. The present family sample comprised 894 Caucasian individuals: 268 patients affected by functional psychosis [58% with illness onset before 18 years, mean age at onset (SD): 14.71 (2.10)], 483 parents and 143 siblings. Ten DTNBP1 single nucleotide polymorphisms were genotyped in all individuals and their transmission disequilibrium was tested in relation to: (i) the risk for psychosis; (ii) patients' age at onset; and (iii) familial neurocognitive performance (including IQ estimation and executive functioning). In early‐onset families a 5‐marker haplotype encompassing exons 2–4 and the surrounding introns was significantly over‐transmitted to cases, while in adult‐onset families two haplotypes corresponding to the region between introns 4 and 7 were over‐transmitted to cases. Estimated IQ was associated with the rs760666 marker in the whole sample, whereas a significant association between executive functioning and the rs2619522 marker appeared in early‐onset families. Our findings confirm the role of the dysbindin‐1 gene in the risk for functional psychosis and show a differential haplotypic risk pattern in families with early as opposed to adult onset in the affected offspring. © 2011 Wiley‐Liss, Inc.

Abnormalities in white matter (WM) volumes and integrity in schizophrenia, together with post-mortem studies showing reduced expression of oligodendrocyte/myelination genes and apoptotic processes taking place in oligodendrocytes, suggest the interest of major regulators of apoptosis as candidate genes for some features related to myelin integrity in schizophrenia. Protein p53, encoded by TP53 gene, has a central role in the control of apoptosis and is involved in oligodendrocyte development. TP53 gene polymorphisms may account for variability in WM features, metabolic activity and biochemical markers of neuronal integrity and membrane turnover. Pro72Arg and Ins16bp polymorphisms at TP53 gene were analyzed in 20 DSM-IV schizophrenia patients. T1/T2-weighted sequences of these patients were acquired using a 1.5 T Philips Gyroscan system. Scans were transformed into Talairach space and segmented into gray matter (GM), WM and cerebrospinal fluid (CSF) using Statistical Parametric Mapping under a ROI approach. Likewise dorsolateral prefrontal cortex (DLPFC) metabolic activity was measured using a procedure based on MRI/PET image fusion. In 13 of these patients proton magnetic resonance spectroscopy was used to examine N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) levels in dorsolateral–medial prefrontal cortex (DLMPFC). MRI data were adjusted for age and brain volume using regression parameters from a healthy control group (n = 45). Patients Pro/Arg heterozygous (Pro72Arg polymorphism) showed a generalized deficit in whole-brain WM that was especially prominent in frontal lobe and a lower metabolic activity in the DLPFC as compared to Pro/Pro homozygous. Pro/Arg subjects also showed decreased NAA/Cho and increased Cho/Cr ratios in right DLMPFC. TP53 genetic variability influences WM volumes in frontal lobes and it seems to modulate the metabolic activity in this region. Our results suggest that TP53 might influence aspects of myelin and white matter integrity which may account for some of the frontal dysfunction features commonly described in these patients.

The neural cell adhesion molecule (NCAM) and its functionally linked polysialyltransferases, ST8SIA2 and ST8SIA4, are crucial for synaptic plasticity. Variations in encoding genes have been associated with mental illness. Since cannabinoids can alter NCAM polysialylation, we hypothesized that delta-9-tetrahydrocannabinol (Δ9-THC) might act as environmental ‘second hit’ regarding cognition of St8sia2−/− mice. These mice show per se minor behavioral abnormalities, consisting of reduced anxiety and mild cognitive deficits. Chronic Δ9-THC treatment of juvenile male wildtype mice (St8sia2+/+) (7 mg/kg every other day over 3 weeks) did not appreciably affect cognition. St8sia2−/− mice, however, displayed a synergistic negative consequence of Δ9-THC on learning/memory, accompanied by polysialic acid-free NCAM-180 reduction in hippocampus and polysialic acid increase in dentate outer molecular layer. These synergistic effects became obvious only months after the last Δ9-THC. We conclude that juvenile cannabis exposure may cause delayed but lasting damage on cognition in subjects genetically predisposed to altered NCAM polysialylation.

Circadian rhythm disturbances are frequently described in psychiatric disorders such as major depressive disorder, bipolar disorder, and schizophrenia. Growing evidence suggests a biological connection between mental health and circadian rhythmicity, including the circadian influence on brain function and mood and the requirement for circadian entrainment by external factors, which is often impaired in mental illness. Mental (as well as physical) health is also adversely affected by circadian misalignment. The marked interindividual differences in this combined susceptibility, in addition to the phenotypic spectrum in traits related both to circadian rhythms and mental health, suggested the possibility of a shared genetic background and that circadian clock genes may also be candidate genes for psychiatric disorders. This hypothesis was further strengthened by observations in animal models where clock genes had been knocked out or mutated. The introduction of genome-wide association studies (GWAS) enabled hypothesis-free testing. GWAS analysis of chronotype confirmed the prominent role of circadian genes in these phenotypes and their extensive polygenicity. However, in GWAS on psychiatric traits, only one clock gene, ARNTL (BMAL1) was identified as one of the few loci differentiating bipolar disorder from schizophrenia, and macaque monkeys where the ARNTL gene has been knocked out display symptoms similar to schizophrenia. Another lesson from genomic analyses is that chronotype has an important genetic correlation with several psychiatric disorders and that this effect is unidirectional. We conclude that the effect of circadian disturbances on psychiatric disorders probably relates to modulation of rhythm parameters and extend beyond the core clock genes themselves.

grant Klinische Forschergruppe (KFO) from the Deutsche Forschungsgemeinschaft (DFG)German Research Foundation (DFG) [241]

Abstract As early detection of symptoms in the subclinical to clinical psychosis spectrum may improve health outcomes, knowing the probabilistic susceptibility of developing a disorder could guide mitigation measures and clinical intervention. In this context, polygenic risk scores (PRSs) quantifying the additive effects of multiple common genetic variants hold the potential to predict complex diseases and index severity gradients. PRSs for schizophrenia (SZ) and bipolar disorder (BD) were computed using Bayesian regression and continuous shrinkage priors based on the latest SZ and BD genome-wide association studies (Psychiatric Genomics Consortium, third release). Eight well-phenotyped groups ( n = 1580; 56% males) were assessed: control ( n = 305), lower ( n = 117) and higher ( n = 113) schizotypy (both groups of healthy individuals), at-risk for psychosis ( n = 120), BD type-I ( n = 359), BD type-II ( n = 96), schizoaffective disorder ( n = 86), and SZ groups ( n = 384). PRS differences were investigated for binary traits and the quantitative Positive and Negative Syndrome Scale. Both BD-PRS and SZ-PRS significantly differentiated controls from at-risk and clinical groups (Nagelkerke’s pseudo- R 2 : 1.3–7.7%), except for BD type-II for SZ-PRS. Out of 28 pairwise comparisons for SZ-PRS and BD-PRS, 9 and 12, respectively, reached the Bonferroni-corrected significance. BD-PRS differed between control and at-risk groups, but not between at-risk and BD type-I groups. There was no difference between controls and schizotypy. SZ-PRSs, but not BD-PRSs, were positively associated with transdiagnostic symptomology. Overall, PRSs support the continuum model across the psychosis spectrum at the genomic level with possible irregularities for schizotypy. The at-risk state demands heightened clinical attention and research addressing symptom course specifiers. Continued efforts are needed to refine the diagnostic and prognostic accuracy of PRSs in mental healthcare.

Mitochondria generate energy through oxidative phosphorylation (OXPHOS). The function of key OXPHOS proteins can be altered by variation in mitochondria-related genes, which may increase the risk of mental illness. We investigated the association of mitochondria-related genes and their genetic risk burden with cognitive performance.We leveraged cross-sectional data from 1320 individuals with a severe psychiatric disorder and 466 neurotypical individuals from the PsyCourse Study. The cognitive tests analyzed were the Trail-Making Test, Verbal Digit Span Test, Digit-Symbol Test, and Multiple Choice Vocabulary Intelligence Test. Association analyses between the cognitive tests, and single-nucleotide polymorphisms (SNPs) mapped to mitochondria-related genes, and their polygenic risk score (PRS) for schizophrenia (SCZ) were performed with PLINK 1.9 and R program.We found a significant association (FDR-adjusted p < 0.05) in the Cytochrome C Oxidase Assembly Factor 8 (COA8) gene locus of the OXPHOS pathway with the Verbal Digit Span (forward) test. Mitochondrial PRS was not significantly associated with any of the cognitive tests.Moderate statistical power due to relatively small sample size.COA8 encodes a poorly characterized mitochondrial protein involved in apoptosis. Here, this gene was associated with the Verbal Digit Span (forward) test, which evaluates short-term memory. Our results warrant replication and may lead to better understanding of cognitive impairment in mental disorders.

Abstract Lithium is regarded as the first-line treatment for bipolar disorder (BD), a severe and disabling mental disorder that affects about 1% of the population worldwide. Nevertheless, lithium is not consistently effective, with only 30% of patients showing a favorable response to treatment. To provide personalized treatment options for bipolar patients, it is essential to identify prediction biomarkers such as polygenic scores. In this study, we developed a polygenic score for lithium treatment response (Li+PGS) in patients with BD. To gain further insights into lithium's possible molecular mechanism of action, we performed a genome-wide gene-based analysis. Using polygenic score modeling, via methods incorporating Bayesian regression and continuous shrinkage priors, Li+PGS was developed in the International Consortium of Lithium Genetics cohort (ConLi+Gen: N=2,367) and replicated in the combined PsyCourse (N=89) and BipoLife (N=102) studies. The associations of Li+PGS and lithium treatment response — defined in a continuous ALDA scale and a categorical outcome (good response vs. poor response) were tested using regression models, each adjusted for the covariates: age, sex, and the first four genetic principal components. Statistical significance was determined at P&lt;����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������

We examined the empirical validity of a staging model of psychotic disorders primarily based on their long-term course. The model distinguished 6 consecutive stages (2A, 2B, 3A, 3B, 4A, 4B) based on symptom recurrence, persistence and progression, such as functional decline. We analyzed data from 243 participants with first-admission psychosis who were followed-up for a mean of 20.9 years and assessed for 22 baseline variables, 23 construct-related variables and 31 outcome variables. Later stages scored significantly poorer than early stages on most validators by showing generally medium to large effect sizes and a dose-response pattern, thus confirming the validity of the model. For each set of validators, differences between consecutive stages were especially evident for stages 2 and 3A, although many variables from each validation realm also differentiated between the consecutive stages 3A and above. Baseline predictors including familial load of schizophrenia, neurodevelopmental impairment, childhood adversity, treatment delay, negative symptoms, neurological impairment and poor early response to treatment, independently accounted for 49.9% of the variance of staging. A staging model of psychosis based primarily on its long-term course has sound construct, outcome and predictive validity, which may inform about stage indicators and predictors of clinical stages from psychosis onset.

Abstract Background Consistent evidence supports the involvement of genetic and environmental factors, and their interactions, in the etiology of psychosis. First-episode psychosis (FEP) comprises a group of disorders that show great clinical and long-term outcome heterogeneity, and the extent to which genetic, familial and environmental factors account for predicting the long-term outcome in FEP patients remains scarcely known. Methods The SEGPEPs is an inception cohort study of 243 first-admission patients with FEP who were followed-up for a mean of 20.9 years. FEP patients were thoroughly evaluated by standardized instruments, with 164 patients providing DNA. Aggregate scores estimated in large populations for polygenic risk score (PRS-Sz), exposome risk score (ERS-Sz) and familial load score for schizophrenia (FLS-Sz) were ascertained. Long-term functioning was assessed by means of the Social and Occupational Functioning Assessment Scale (SOFAS). The relative excess risk due to interaction (RERI) was used as a standard method to estimate the effect of interaction of risk factors. Results Our results showed that a high FLS-Sz gave greater explanatory capacity for long-term outcome, followed by the ERS-Sz and then the PRS-Sz. The PRS-Sz did not discriminate significantly between recovered and non-recovered FEP patients in the long term. No significant interaction between the PRS-Sz, ERS-Sz or FLS-Sz regarding the long-term functioning of FEP patients was found. Conclusions Our results support an additive model of familial antecedents of schizophrenia, environmental risk factors and polygenic risk factors as contributors to a poor long-term functional outcome for FEP patients.

Schizophrenia (SCZ) is a complex disorder that typically arises in late adolescence or early adulthood. Age at onset (AAO) of SCZ is associated with long-term outcomes of the disease. We explored the genetic architecture of AAO with a genome-wide association study (GWAS), heritability, polygenic risk score (PRS), and copy number variant (CNV) analyses in 4 740 subjects of European ancestry. Although no genome-wide significant locus was identified, SNP-based heritability of AAO was estimated to be between 17 and 21%, indicating a moderate contribution of common variants. We also performed cross-trait PRS analyses with a set of mental disorders and identified a negative association between AAO and common variants for SCZ, childhood maltreatment and attention-deficit/hyperactivity disorder. We also investigated the role of copy number variants (CNVs) in AAO and found an association with the length and number of deletions (P-value = 0.03), whereas the presence of CNVs previously reported in SCZ was not associated with earlier onset. To our knowledge, this is the largest GWAS of AAO of SCZ to date in individuals from European ancestry, and the first study to determine the involvement of common variants in the heritability of AAO. Finally, we evidenced the role played by higher SCZ load in determining AAO but discarded the role of pathogenic CNVs. Altogether, these results shed light on the genetic architecture of AAO, which needs to be confirmed with larger studies.

Abstract Schizophrenia may represent a trade-off in the evolution of human-specific ontogenetic mechanisms that guide neurodevelopment. Human Accelerated Regions (HARs) are evolutionary markers functioning as neurodevelopmental transcription enhancers that have been associated with brain configuration, neural information processing, and schizophrenia risk. Here, we have investigated the influence of HARs’ polygenic load on neuroanatomical measures through a case-control approach (128 patients with schizophrenia and 115 controls). To this end, we have calculated the global schizophrenia Polygenic Risk Score (Global PRS SZ ) and that specific to HARs (HARs PRS SZ ). We have also estimated the polygenic burden restricted to the HARs linked to transcriptional regulatory elements active in the foetal brain (FB-HARs PRS SZ ) and the adult brain (AB-HARs PRS SZ ). We have explored the main effects of the PRSs and the PRSs x diagnosis interactions on brain regional cortical thickness (CT) and surface area (SA). The results indicate that a higher FB-HARs PRS SZ is associated with patients’ lower SA in the lateral orbitofrontal cortex, the superior temporal cortex, the pars triangularis and the paracentral lobule. While noHARs-derived PRSs show an effect on the risk, our neuroanatomical findings suggest that the human-specific transcriptional regulation during the prenatal period underlies SA variability, highlighting the role of these evolutionary markers in the schizophrenia genomic architecture.

Antipsychotic-induced weight gain (AIWG) is a common adverse event in schizophrenia. Genome-wide association studies (GWAS) and polygenic risk scores (PRS) for other diseases or traits are recent approaches to disentangling the genetic architecture of AIWG. 200 patients with schizophrenia treated monotherapeutically with antipsychotics were included in this study. A multiple linear regression analysis with ten-fold crossvalidation was performed to predict the percentage weight change after five weeks of treatment. Independent variables were sex, age, body mass index (BMI) at baseline, medication-associated risk, and PRSs (BMI, schizophrenia, diabetes, and metabolic syndrome). An explorative GWAS analysis was performed on the same subjects and traits. PRSs for BMI (β = 3.78; p = 0.0041), schizophrenia (β = 5.38; p = 0.021) and diabetes type 2 (β = 13.4; p = 0.046) were significantly associated with AIWG. Other significant factors were sex, baseline BMI and medication. Compared to the model without genetic factors, the addition of PRSs for BMI, schizophrenia, and diabetes type 2 increased the goodness of fit by 6.5 %. The GWAS identified the association of three variants (rs10668573, rs10249381 and rs1988834) with AIWG at a genome-wide level of p < 1 · 10−6. Using PRS for schizophrenia, BMI, and diabetes type 2 increased the explained variation of predicted weight gain, compared to a model without PRSs. For more precise results, PRSs derived from other traits (ideally AIWG) should be investigated. Potential risk variants identified in our GWAS need to be further investigated and replicated in independent samples.

Schizophrenia (SCZ) is a genetically heterogenous psychiatric disorder of highly polygenic nature. Correlative evidence from genetic studies indicate that the aggregated effects of distinct genetic risk factor combinations found in each patient converge onto common molecular mechanisms. To prove this on a functional level, we employed a reductionistic cellular model system for polygenic risk by differentiating induced pluripotent stem cells (iPSCs) from 104 individuals with high polygenic risk load and controls into cortical glutamatergic neurons (iNs). Multi-omics profiling identified widespread differences in alternative polyadenylation (APA) in the 3' untranslated region of many synaptic transcripts between iNs from SCZ patients and healthy donors. On the cellular level, 3'APA was associated with a reduction in synaptic density of iNs. Importantly, differential APA was largely conserved between postmortem human prefrontal cortex from SCZ patients and healthy donors, and strongly enriched for transcripts related to synapse biology. 3'APA was highly correlated with SCZ polygenic risk and affected genes were significantly enriched for SCZ associated common genetic variation. Integrative functional genomic analysis identified the RNA binding protein and SCZ GWAS risk gene PTBP2 as a critical trans-acting factor mediating 3'APA of synaptic genes in SCZ subjects. Functional characterization of PTBP2 in iNs confirmed its key role in 3'APA of synaptic transcripts and regulation of synapse density. Jointly, our findings show that the aggregated effects of polygenic risk converge on 3'APA as one common molecular mechanism that underlies synaptic impairments in SCZ.

Zusammenfassung Hintergrund Intensivmedizinische Aufenthalte führen bei vorbelasteten Menschen häufig zu Symptomen einer posttraumatischen Belastungsstörung (Post-ICU-PTBS). In der Nachsorge spielen HausärztInnen eine wichtige Rolle. Falldarstellung Eine 58-jährige Patientin entwickelt nach erlebter Sepsis eine Post-ICU-PTBS. Sie erhält durch ihre Hausärztin eine Kurzform der Narrativen Expositionstherapie (NET) und erfährt eine deutliche Symptombesserung. Schlussfolgerung Die angewandte Kurzform der NET kann für die Behandlung von leicht- bis mittelgradigen Symptomen einer Post-ICU-PTBS geeignet sein.

Lithium is the gold standard treatment for bipolar disorder (BD). However, its mechanism of action is incompletely understood, and prediction of treatment outcomes is limited. In our previous multi-omics study of the Pharmacogenomics of Bipolar Disorder (PGBD) sample combining transcriptomic and genomic data, we found that focal adhesion, the extracellular matrix (ECM), and PI3K-Akt signaling networks were associated with response to lithium. In this study, we replicated the results of our previous study using network propagation methods in a genome-wide association study of an independent sample of 2039 patients from the International Consortium on Lithium Genetics (ConLiGen) study. We identified functional enrichment in focal adhesion and PI3K-Akt pathways, but we did not find an association with the ECM pathway. Our results suggest that deficits in the neuronal growth cone and PI3K-Akt signaling, but not in ECM proteins, may influence response to lithium in BD.

Cognitive deficits are already present before psychosis onset but are a key feature of first-episode psychosis (FEP). The objective of this study was to investigate the cognitive outcomes of a cohort of FEP patients who were diagnosed using the clinical staging approach and were followed for up to 21 years. We analyzed data from 173 participants with first-admission psychosis who were followed-up for a mean of 20.9 years. The clinical staging assessment was adapted from the clinical staging framework developed by McGorry et al.1 Cognitive assessment was performed using the MATRICS Consensus Cognitive Battery (MMCB) at the end of follow-up. FEP patients who were longitudinally diagnosed in the lowest clinical stages (stages 2A and 2B) showed better performance in attention, processing speed, and MCCB overall composite score than those in the highest clinical stages (stages 4A and 4B). There was a significant linear trend association between worsening of all MCCB cognitive functions and MCCB overall composite score and progression in clinical staging. Furthermore, the interval between two and five years of follow-up appears to be associated with deficits in processing speed as a cognitive marker. Our results support the validation of the clinical staging model over a long-term course of FEP based on neuropsychological performance. A decline in some cognitive functions, such as processing speed, may facilitate the transition of patients to an advanced stage during the critical period of first-episode psychosis.

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The link between bipolar disorder (BP) and immune dysfunction remains controversial. While epidemiological studies have long suggested an association, recent research has found only limited evidence of such a relationship. To clarify this, we performed an exploratory study of the contributions of immune-relevant genetic factors to the response to lithium (Li) treatment and the clinical presentation of BP. First, we assessed the association of a large collection of immune-related genes (4925) with Li response, defined by the Retrospective Assessment of the Lithium Response Phenotype Scale (Alda scale), and clinical characteristics in patients with BP from the International Consortium on Lithium Genetics (ConLi+Gen, N = 2374). Second, we calculated here previously published polygenic scores (PGSs) for immune-related traits and evaluated their associations with Li response and clinical features. Overall, we observed relatively weak associations (p < 1 × 10-4) with BP phenotypes within immune-related genes. Network and functional enrichment analyses of the top findings from the association analyses of Li response variables showed an overrepresentation of pathways participating in cell adhesion and intercellular communication. These appeared to converge on the well-known Li-induced inhibition of GSK-3β. Association analyses of age-at-onset, number of mood episodes, and presence of psychosis, substance abuse and/or suicidal ideation suggested modest contributions of genes such as RTN4, XKR4, NRXN1, NRG1/3 and GRK5 to disease characteristics. PGS analyses returned weak associations (p < 0.05) between inflammation markers and the studied BP phenotypes. Our results suggest a modest relationship between immunity and clinical features in BP. More research is needed to assess the potential therapeutic relevance.

Abstract The response variability to repetitive transcranial magnetic stimulation (rTMS) challenges the effective use of this treatment option in patients with schizophrenia. This variability may be deciphered by leveraging predictive information in structural MRI, clinical, sociodemographic, and genetic data using artificial intelligence. We developed and cross-validated rTMS response prediction models in patients with schizophrenia drawn from the multisite RESIS trial. The models incorporated pre-treatment sMRI, clinical, sociodemographic, and polygenic risk score (PRS) data. Patients were randomly assigned to receive active ( N = 45) or sham ( N = 47) rTMS treatment. The prediction target was individual response, defined as ≥20% reduction in pre-treatment negative symptom sum scores of the Positive and Negative Syndrome Scale. Our multimodal sequential prediction workflow achieved a balanced accuracy (BAC) of 94% (non-responders: 92%, responders: 95%) in the active-treated group and 50% in the sham-treated group. The clinical, clinical + PRS, and sMRI-based classifiers yielded BACs of 65%, 76%, and 80%, respectively. Apparent sadness, inability to feel, educational attainment PRS, and unemployment were most predictive of non-response in the clinical + PRS model, while grey matter density reductions in the default mode, limbic networks, and the cerebellum were most predictive in the sMRI model. Our sequential modelling approach provided superior predictive performance while minimising the diagnostic burden in the clinical setting. Predictive patterns suggest that rTMS responders may have higher levels of brain grey matter in the default mode and salience networks which increases their likelihood of profiting from plasticity-inducing brain stimulation methods, such as rTMS. The future clinical implementation of our models requires findings to be replicated at the international scale using stratified clinical trial designs.

Lithium (Li) is the first-line treatment for bipolar disorder (BD) even though only 30 % of BD patients are considered excellent responders. The mechanisms by which Li exerts its action are not clearly understood, but it has been suggested that specific epigenetic mechanisms, such as methylation processes, may play a role. In this regard, DNA methylation patterns can be used to estimate epigenetic age (EpiAge), which is accelerated in BD patients and reversed by Li treatment. Our first aim was to compare the DNA methylation profile in peripheral blood between BD patients categorized as excellent responders to Li (Ex-Rp) and non-responders (N-Rp). Secondly, EpiAge was estimated to detect differential age acceleration between the two groups. A total of 130 differentially methylated positions (DMPs) and 16 differentially methylated regions (DMRs) between Ex-Rp (n = 26) and N-Rp (n = 37) were identified (FDR adjusted p-value < 0.05). We found 122 genes mapping the DMPs and DMRs, nine of which (HOXB6, HOXB3, HOXB-AS3, TENM2, CACNA1B, ANK3, EEF2K, CYP1A1, and SORCS2) had previously been linked to Li response. We found genes related to the GSK3β pathway to be highly represented. Using FUMA, we found enrichment in Gene Ontology Cell Component for the synapse. Gene network analysis highlighted functions related to the cell cycle, nervous system development and function, and gene expression. No significant differences in age acceleration were found between Ex-Rp and N-Rp for any of the epigenetic clocks analysed. Our findings indicate that a specific methylation pattern could determine the response to Li in BD patients. We also found that a significant portion of the differentially methylated genes are closely associated with the GSK3β pathway, reinforcing the role of this system in Li response. Future longitudinal studies with larger samples will help to elucidate the epigenetic mechanisms underlying Li response.

Optical coherence tomography (OCT) and electroretinography (ERG) studies have revealed structural and functional retinal alterations in individuals with schizophrenia spectrum disorders (SSD). However, it remains unclear which specific retinal layers are affected, how the retina, brain, and clinical symptomatology are connected, and how alterations of the visual system are related to genetic disease risk.OCT, ERG, and brain magnetic resonance imaging (MRI) were applied to comprehensively investigate the visual system in a cohort of 103 patients with SSD and 130 healthy control individuals. The sparse partial least squares (SPLS) algorithm was used to identify multivariate associations between clinical disease phenotype and biological alterations of the visual system. The association of the revealed patterns with the individual polygenetic disease risk for schizophrenia was explored in a post hoc analysis. In addition, covariate-adjusted case-control comparisons were performed for each individual OCT and ERG parameter.The SPLS analysis yielded a phenotype-eye-brain signature of SSD in which greater disease severity, longer duration of illness, and impaired cognition were associated with electrophysiological alterations and microstructural thinning of most retinal layers. Higher individual loading onto this disease-relevant signature of the visual system was significantly associated with elevated polygenic risk for schizophrenia. In case-control comparisons, patients with SSD had lower macular thickness, thinner retinal nerve fiber and inner plexiform layers, less negative a-wave amplitude, and lower b-wave amplitude.This study demonstrates multimodal microstructural and electrophysiological retinal alterations in individuals with SSD that are associated with disease severity and individual polygenetic burden.

<title>Abstract</title> Micro RNAs (miRNAs) play a crucial role as regulators of various biological processes and have been implicated in the pathogenesis of mental disorders such as schizophrenia and bipolar disorders. In this study, we investigate the expression patterns of miRNAs in the PsyCourse Study (n=1,786), contrasting three broad diagnostic groups: Psychotic (Schizophrenia-spectrum disorders), Affective (Bipolar Disorder I, II and recurrent Depression), and neurotypic healthy individuals. Through comprehensive analyses, including differential miRNA expression, miRNA transcriptome-wide association study (TWAS), and predictive modelling, we identified multiple miRNAs unique to Psychotic and Affective groups as well as shared by both. Furthermore, we performed integrative analysis to identify the target genes of the dysregulated miRNAs and elucidate their potential roles in psychosis. Our findings reveal significant alterations of multiple miRNAs such as miR-584-3p and miR-99b-5p across the studied diagnostic groups, highlighting their role as molecular correlates. Additionally, the miRNA TWAS analysis discovered previously known and novel genetically dysregulated miRNAs confirming the relevance in the etiology of the diagnostic groups. Importantly, novel factors and putative molecular mechanisms underlying these groups were uncovered through the integration of miRNA-target gene interactions. This comprehensive investigation provides valuable insights into the molecular underpinnings of severe mental disorders, shedding light on the complex regulatory networks involving miRNAs.

Abstract Introduction Lithium remains the best-established long-term treatment for bipolar disorder because of its efficacy in maintaining periods of remission and reducing the risk of suicide. Not all patients successfully respond to lithium treatment, and the individual response, including the occurrence of side effects, is highly variable and not easy to predict. The genetic basis of lithium response is supported by the fact that the response clusters in families. Likewise, recent high-throughput genomic analyses have shed light on its genetic architecture. Methods This nonsystematic review summarizes the main results obtained in genetic association studies using lithium response as target trait. Results These studies suggest that several genetic loci might modulate the way a patient responds to lithium maintenance treatment. Further studies to fully characterize the genetic architecture of lithium response are warranted. Discussion The identification of genetic factors associated with lithium response will be important for (1) better understanding of lithium’s mode of action and (2) development of a predictive model for optimization of long-term treatment of bipolar disorder.

Abstract Hippocampal volume decrease is a structural hallmark of schizophrenia (SCZ), and convergent evidence from postmortem and imaging studies suggests that it may be explained by changes in the cytoarchitecture of the cornu ammonis 4 (CA4) and dentate gyrus (DG) subfields. Increasing evidence indicates that aerobic exercise increases hippocampal volume in CA subfields and improves cognition in SCZ patients. Previous studies showed that the effects of exercise on the hippocampus might be connected to the polygenic burden of SCZ risk variants. However, little is known about cell type-specific genetic contributions to these structural changes. In this secondary analysis, we evaluated the modulatory role of cell type-specific SCZ polygenic risk scores (PRS) on volume changes in the CA1, CA2/3, and CA4/DG subfields over time. We studied 20 multi-episode SCZ patients and 23 healthy controls who performed aerobic exercise, and 21 multi-episode SCZ patients allocated to a control intervention (table soccer) for 3 months. Magnetic resonance imaging-based assessments were performed with FreeSurfer at baseline and after 3 months. The analyses showed that the polygenic burden associated with oligodendrocyte precursor cells (OPC) and radial glia (RG) significantly influenced the volume changes between baseline and 3 months in the CA4/DG subfield in SCZ patients performing aerobic exercise. A higher OPC- or RG-associated genetic risk burden was associated with a less pronounced volume increase or even a decrease in CA4/DG during the exercise intervention. We hypothesize that SCZ cell type-specific polygenic risk modulates the aerobic exercise-induced neuroplastic processes in the hippocampus.

Stressful life events influence the course of affective disorders, however, the mechanisms by which they bring about phenotypic change are not entirely known.We explored the role of DNA methylation in response to recent stressful life events in a cohort of bipolar patients from the longitudinal PsyCourse study (n = 96). Peripheral blood DNA methylomes were profiled at two time points for over 850,000 methylation sites. The association between impact ratings of stressful life events and DNA methylation was assessed, first by interrogating methylation sites in the vicinity of candidate genes previously implicated in the stress response and, second, by conducting an exploratory epigenome-wide association analysis. Third, the association between epigenetic aging and change in stress and symptom measures over time was investigated.Investigation of methylation signatures over time revealed just over half of the CpG sites tested had an absolute difference in methylation of at least 1% over a 1-year period. Although not a single CpG site withstood correction for multiple testing, methylation at one site (cg15212455) was suggestively associated with stressful life events (p < 1.0 × 10-5). Epigenetic aging over a 1-year period was not associated with changes in stress or symptom measures.To the best of our knowledge, our study is the first to investigate epigenome-wide methylation across time in bipolar patients and in relation to recent, non-traumatic stressful life events. Limited and inconclusive evidence warrants future longitudinal investigations in larger samples of well-characterized bipolar patients to give a complete picture regarding the role of DNA methylation in the course of bipolar disorder.

Bipolar affective disorder (BD) is a severe psychiatric illness, for which lithium (Li) is the gold standard for acute and maintenance therapies. The therapeutic response to Li in BD is heterogeneous and reliable biomarkers allowing patients stratification are still needed. A GWAS performed by the International Consortium on Lithium Genetics (ConLiGen) has recently identified genetic markers associated with treatment responses to Li in the human leukocyte antigens (HLA) region. To better understand the molecular mechanisms underlying this association, we have genetically imputed the classical alleles of the HLA region in the European patients of the ConLiGen cohort. We found our best signal for amino-acid variants belonging to the HLA-DRB1*11:01 classical allele, associated with a better response to Li (p < 1 × 10-3; FDR < 0.09 in the recessive model). Alanine or Leucine at position 74 of the HLA-DRB1 heavy chain was associated with a good response while Arginine or Glutamic acid with a poor response. As these variants have been implicated in common inflammatory/autoimmune processes, our findings strongly suggest that HLA-mediated low inflammatory background may contribute to the efficient response to Li in BD patients, while an inflammatory status overriding Li anti-inflammatory properties would favor a weak response.

Bipolar disorder (BD) has a highly heterogeneous clinical course that is characterized by relapses and increased health care utilization in a significant fraction of patients. A thorough understanding of factors influencing illness course is essential for predicting disorder severity and developing targeted therapies. We performed polygenic score analyses in four cohorts (N = 954) to test whether the genetic risk for BD, schizophrenia, or major depression is associated with a severe course of BD. We analyzed BD patients with a minimum illness duration of five years. The severity of the disease course was assessed by using the number of hospitalizations in a mental health facility and a composite measure of longitudinal illness severity (OPCRIT item 90). Our analyses showed that higher polygenic scores for BD (β = 0.11, SE = 0.03, p = 1.17 × 10-3) and schizophrenia (β = 0.09, SE = 0.03, p = 4.24 × 10−3), but not for major depression, were associated with more hospitalizations. None of the investigated polygenic scores was associated with the composite measure of longitudinal illness severity (OPCRIT item 90). We could not account for non-genetic influences on disease course. Our clinical sample contained more severe cases. This study demonstrates that the genetic risk burden for psychiatric illness is associated with increased health care utilization, a proxy for disease severity, in BD patients. The findings are in line with previous observations made for patients diagnosed with schizophrenia or major depression. Therefore, in the future psychiatric disorder polygenic scores might become helpful for stratifying patients with high risk of a chronic manifestation and predicting disease course.

Translational research on complex, multifactorial mental health disorders, such as bipolar disorder, major depressive disorder, schizophrenia, and substance use disorders requires databases with large-scale, harmonized, and integrated real-world and research data. The Munich Mental Health Biobank (MMHB) is a mental health-specific biobank that was established in 2019 to collect, store, connect, and supply such high-quality phenotypic data and biosamples from patients and study participants, including healthy controls, recruited at the Department of Psychiatry and Psychotherapy (DPP) and the Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital of the Ludwig-Maximilians-University (LMU), Munich, Germany. Participants are asked to complete a questionnaire that assesses sociodemographic and cross-diagnostic clinical information, provide blood samples, and grant access to their existing medical records. The generated data and biosamples are available to both academic and industry researchers. In this manuscript, we outline the workflow and infrastructure of the MMHB, describe the clinical characteristics and representativeness of the sample collected so far, and reveal future plans for expansion and application. As of 31 October 2021, the MMHB contains a continuously growing set of data from 578 patients and 104 healthy controls (46.37% women; median age, 38.31 years). The five most common mental health diagnoses in the MMHB are recurrent depressive disorder (38.78%; ICD-10: F33), alcohol-related disorders (19.88%; ICD-10: F10), schizophrenia (19.69%; ICD-10: F20), depressive episode (15.94%; ICD-10: F32), and personality disorders (13.78%; ICD-10: F60). Compared with the average patient treated at the recruiting hospitals, MMHB participants have significantly more mental health-related contacts, less severe symptoms, and a higher level of functioning. The distribution of diagnoses is also markedly different in MMHB participants compared with individuals who did not participate in the biobank. After establishing the necessary infrastructure and initiating recruitment, the major tasks for the next phase of the MMHB project are to improve the pace of participant enrollment, diversify the sociodemographic and diagnostic characteristics of the sample, and improve the utilization of real-world data generated in routine clinical practice.

Abstract Polygenic risk prediction remains an important aim of genetic association studies. Currently, the predictive power of schizophrenia polygenic risk scores (PRSs) is not large enough to allow highly accurate discrimination between cases and controls and thus is not adequate for clinical integration. Since PRSs are rarely used to reveal biological functions or to validate candidate pathways, to fill this gap, we investigated whether their predictive ability could be improved by building genome-wide (GW-PRSs) and pathway-specific PRSs, using distance- or expression quantitative trait loci (eQTLs)- based mapping between genetic variants and genes. We focused on five pathways (glutamate, oxidative stress, GABA/interneurons, neuroimmune/neuroinflammation and myelin) which belong to a critical hub of schizophrenia pathophysiology, centred on redox dysregulation/oxidative stress. Analyses were first performed in the Lausanne Treatment and Early Intervention in Psychosis Program (TIPP) study ( n = 340, cases/controls: 208/132), a sample of first-episode of psychosis patients and matched controls, and then validated in an independent study, the epidemiological and longitudinal intervention program of First-Episode Psychosis in Cantabria (PAFIP) ( n = 352, 224/128). Our results highlighted two main findings. First, GW-PRSs for schizophrenia were significantly associated with early psychosis status. Second, oxidative stress was the only significantly associated pathway that showed an enrichment in both the TIPP ( p = 0.03) and PAFIP samples ( p = 0.002), and exclusively when gene-variant linking was done using eQTLs. The results suggest that the predictive accuracy of polygenic risk scores could be improved with the inclusion of information from functional annotations, and through a focus on specific pathways, emphasizing the need to build and study functionally informed risk scores.

Abstract The synaptic vesicular monoamine transporter (SVMT) plays a key role in monoaminergic neurotransmission determining the size of neurotransmitter vesicular pools available for exocytotic release. Recently, several lines of evidence have suggested that altered functions of SVMT may be involved in the pathogenesis of certain neuropsychiatric diseases, including psychotic and mood disorders. In the present study, we tested the potential involvement of SVMT gene variants in the etiology of schizophrenia and bipolar disorder. Five different SNPs (T440G, C1368T, T2666C, A2683C, and A745G) were included in the analysis covering a region of about 35 kb along the SVMT gene. Analyses were performed in a case‐control sample consisting of 88 bipolar patients, 107 subjects with schizophrenia, and 164 controls. Two risk haplotypes for both schizophrenia and bipolar disorder in SVMT gene were identified. Particularly, 2666T‐2683A‐745G (TAG) and 2666C‐2683C‐745A (CCA) combinations were significantly more frequent in both bipolar and schizophrenic patients than in controls. UNPHASED package estimated haplotype effects for all patients yielded relative risks of 4.1 (95%CI: 1.83–9.21) for TAG combination and 2.336 (95%CI: 1.28–4.26) for CCA haplotype. Conversely, 2666T‐2683C‐745A (TCA) and 2666C‐2683A‐745G (CAG) haplotypes seemed to protect against these mental disorders, since the estimated frequency in control chromosomes was 12% whilst such haplotypes were not observed in any bipolar or schizophrenic subject ( P &lt; 0.0000). Our results strongly suggest that SVMT gene or certain regions of it may constitute a genetic substrate of susceptibility for both schizophrenia and bipolar disorder. © 2007 Wiley‐Liss, Inc.

Khat trees are native to East Africa and the Arabian peninsula. Their leaves contain amphetamine-like alkaloids such as cathinone, cathine and norephedrine, and are chewed for their stimulating and euphorigenic effects1. Khat use varies by season: in the dry season, there is limited availability and market prices are high; in the rainy season, the opposite is true. Excessive use is associated with dependence and khat-induced psychosis2. In collaboration with the Gilgel Gibe Field Research Center of Jimma University, in Southwestern Ethiopia, we studied khat use and khat-induced psychotic symptoms in 1,100 men aged 18 to 40 years (mean 28.4 ± 6.6), randomly selected from the center's population registry. Trained raters interviewed participants at two subsequent time points, i.e. during the dry season (T1; N=853) and during the rainy season, nine months later (T2; N=695). They explored khat use during the past 7 days using the Timeline Followback Method Assessment. Psychotic symptoms experienced during the past 6 months were assessed by four items from the Composite International Diagnostic Interview (CIDI) selected on the basis of previous studies3. Khat-induced psychotic symptoms were defined as being present during or up to 6 hours after consumption and assessed with supplementary questions3. Potentially traumatic experiences (e.g., assault or life-threatening injury) during the period up to T1 or since T1 were explored by an adapted version of the Life Events Checklist for DSM-5 (LEC-5)4. A cut-off of four experiences was fixed by median split. Urine samples were collected to analyze khat alkaloids through immunoassay tests for amphetamine. Khat use in the past 7 days was reported by 599 individuals (70.2%) at T1, and 565 (81.3%) at T2. The 6-month prevalence of khat-induced psychotic symptoms was 7.9% at T1 and 12.8% at T2. At T2, we found 225 individuals with a positive immunoassay test. In these subjects, the rate of khat-induced psychotic symptoms was 26.6% among those with a history of four or more past traumatic experiences (N=124) and 14.0% among those with a history of less than four of those experiences (N=121) (p=0.015). This result could not be explained by higher khat use among the high trauma group (p>0.081 for all use indicators in the last 7 days among people with high vs. low trauma load). We also observed that recent trauma exposure was associated with elevated presence of khat-induced psychotic symptoms in individuals with low trauma exposure during the period up to T1 (with recent trauma: 28%; without recent trauma: 12%; p=0.009). Among individuals with high trauma exposure during that period, additional recent trauma did not have this effect (with recent trauma: 25%; without recent trauma: 26%; p=0.933). Our findings suggest that, in the general male population of an African country, traumatic experiences can sensitize to the effects of a psychomimetic substance. This is in line with the behavioral sensitization paradigm, which suggests that repeated administration of amphetamines or exposure to stress can cause sensitization of dopamine neurons and consequently a higher dopamine release in response to subsequent stress or amphetamine, which facilitates the development of psychotic symptoms5-7. Kristina Adorjan1-3, Michael Odenwald4,5, Marina Widmann4,5, Markos Tesfaye6, Fasil Tessema6, Stefan Toennes7, Sultan Suleman6, Sergi Papiol1, Matiwos Soboka6, Zeleke Mekonnen6, Brigitte Rockstroh4,5, Marcella Rietschel8, Oliver Pogarell2, Ezra Susser9,10, Thomas G. Schulze1 1Institute of Psychiatric Phenomics and Genomics, Medical Center of University of Munich, Munich, Germany; 2Department of Psychiatry and Psychotherapy, Medical Center of University of Munich, Munich, Germany; 3Center for International Health, University of Munich, Munich, Germany; 4University of Konstanz, Konstanz, Germany; 5vivo international e.V., Germany; 6Jimma University, Jimma, Ethiopia; 7Goethe University, Frankfurt am Main, Germany; 8Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany; 9Mailman School of Public Health, Columbia University, New York, NY, USA; 10New York State Psychiatric Institute, New York, NY, USA The authors acknowledge support by the Dr. Lisa Oehler Foundation, Kassel, Germany. The first two as well as the last two authors contributed equally to this work.

Although the mood stabilizer lithium is a first-line treatment in bipolar disorder, a substantial number of patients do not benefit from it and experience side effects. No clinical tool is available for predicting lithium response or the occurrence of side effects in everyday clinical practice. Multiple genetic research efforts have been performed in this field because lithium response and side effects are considered to be multifactorial endophenotypes. Available results from linkage and segregation, candidate-gene, and genome-wide association studies indicate a role of genetic factors in determining response and side effects. For example, candidate-gene studies often report GSK3β, brain-derived neurotrophic factor, and SLC6A4 as being involved in lithium response, and the latest genome-wide association study found a genome-wide significant association of treatment response with a locus on chromosome 21 coding for two long non-coding RNAs. Although research results are promising, they are limited mainly by a lack of replicability and, despite the collaboration of consortia, insufficient sample sizes. The need for larger sample sizes and “multi-omics” approaches is apparent, and such approaches are crucial for choosing the best treatment options for patients with bipolar disorder. In this article, we delineate the mechanisms of action of lithium and summarize the results of genetic research on lithium response and side effects.

Two recently described adjacent DNA polymorphisms [(GT)12-18 and (CT)4-5] in the 5'-regulatory region of 5-HT2C receptor gene were analysed in a sample of 88 bipolar patients and 162 controls, all of Spanish origin. Statistical analyses revealed no overall allele or genotype associations with the disease. A haplotype analyses between the (GT)12-18/(CT)4-5 motif and a Cys23Ser variant of the 5-HT2C gene (which had previously been genotyped in the same sample) showed similar distributions between cases and controls. Only a slight increase of s-Ser23 haplotype was found in the subgroup of bipolar women with family history of psychiatric illness (OR=1.24 [95%CI: 1.12-1.38]).

Abstract By pure endpoint diagnosis of the disease, the risk of developing schizophrenia has been repeatedly associated with specific variants of the neuregulin1 ( NRG1 ) gene. However, the role of NRG1 in the etiology of schizophrenia has remained unclear. Since Nrg1 serves vital functions in early brain development of mice, we hypothesized that human NRG1 alleles codetermine developmentally influenced readouts of the disease: age of onset and positive symptom severity. We analyzed 1,071 comprehensively phenotyped schizophrenic/schizoaffective patients, diagnosed according to DSM‐IV‐TR, from the GRAS (Göttingen Research Association for Schizophrenia) Data Collection for genetic variability in the Icelandic region of risk in the NRG1 gene. For the case‐control analysis part of the study, we included 1,056 healthy individuals with comparable ethnicity. The phenotype‐based genetic association study (PGAS) was performed on the GRAS sample. Instead of a risk constellation, we detected that several haplotypic variants of NRG1 were, unexpectedly, less frequent in the schizophrenic than in the control sample (mean OR = 0.78, range between 0.68 and 0.85). In the PGAS we found that these “protective” NRG1 variants are specifically underrepresented in subgroups of schizophrenic subjects with early age of onset and high positive symptom load. The GRAS Data Collection as a prerequisite for PGAS has enabled us to associate protective NRG1 genotypes with later onset and milder course of schizophrenia. © 2011 Wiley‐Liss, Inc.