Association of polygenic score and the involvement of cholinergic and glutamatergic pathways with lithium treatment response in patients with bipolar disorder.

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.

Using polygenic scores and clinical data for bipolar disorder patient stratification and lithium response prediction: machine learning approach.

BACKGROUND: 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. AIMS: To use a combination of transdiagnostic genetic and clinical factors to predict lithium response in patients with bipolar disorder. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.

Association of polygenic score for major depression with response to lithium in patients with bipolar disorder.

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.

Investigating the phenotypic and genetic associations between personality traits and suicidal behavior across major mental health diagnoses.

Personality traits influence risk for suicidal behavior. We examined phenotype- and genotype-level associations between the Big Five personality traits and suicidal ideation and attempt in major depressive, bipolar and schizoaffective disorder, and schizophrenia patients (N = 3012) using fixed- and random-effects inverse variance-weighted meta-analyses. Suicidal ideations were more likely to be reported by patients with higher neuroticism and lower extraversion phenotypic scores, but showed no significant association with polygenic load for these personality traits. Our findings provide new insights into the association between personality and suicidal behavior across mental illnesses and suggest that the genetic component of personality traits is unlikely to have strong causal effects on suicidal behavior.

Quality of life and subjective sleep-related measures in bipolar disorder and major depressive disorder.

PURPOSE: Diminished quality of life (QoL) has been reported in patients with mood disorders. QoL has also been shown to be decreased by sleep disturbances. Since sleep disorders are common in mood disorders, the aim of this study was to determine whether sleep characteristics are associated to QoL among patients with Bipolar Disorder (BD) and unipolar Major Depressive Disorders (MDD). METHODS: QoL was assessed in 170 patients with mood disorders (61 BD and 109 MDD), who also completed questionnaires measuring the severity of insomnia, sleepiness, chronotype preference and obstructive sleep apnea (OSA) probability index. RESULTS: Analyses showed that BD and MDD groups had similar QoL and sleep measures but the MDD group had higher OSA scores. In BD, correlations indicated a relationship between QoL and insomnia complaints and sleepiness, whereas in MDD, correlations indicated an association between QoL and insomnia complaints and OSA score. In both groups, QoL was related to depressive symptomatology. Linear regressions showed that, in BD, QoL was related to insomnia complaints and sleepiness even in the euthymic state, whereas in MDD, QoL was related to insomnia complaints but not in euthymic patients. CONCLUSION: QoL is related to sleep differently in BD and MDD. The results suggest that insomnia and sleepiness are particularly high in BD even when patients are euthymic. These findings suggest that focusing on insomnia and sleepiness during different mood states of BD could increase QoL.

Is Coping with Stigma by Association Role-Specific for Different Family Members? A Qualitative Study with Bipolar Disorder Patients' Relatives.

Trying to cope with stigma by association (SBA) often results in behaviors leading to social isolation and withdrawal. This study aimed at exploring the stigma-related experiences of family members of persons living with bipolar disorder (PW-BD). A semi-structured interview was conducted with relatives of PW-BD. Open-ended questions addressed three issues: awareness of public stigma of bipolar disorder, experiences of associative stigma, and ways of coping with experiences of SBA. Data were collected from a purposive sample of 21 family members. Experiences of SBA were specifically related to the different family roles. Parents had to deal with responsibility, partners with the choice of staying or not, and siblings with "a sort of duty." These specific prejudices enhanced specific coping strategies. This is the first study to highlight specific issues and coping from the perspective of family members. Based on these findings, specific targeted interventions could be developed.

Characterisation of age and polarity at onset in bipolar disorder.

BACKGROUND: 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. AIMS: To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics. METHOD: 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. RESULTS: 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 (ß = -0.34 years, s.e. = 0.08), major depression (ß = -0.34 years, s.e. = 0.08), schizophrenia (ß = -0.39 years, s.e. = 0.08), and educational attainment (ß = -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. CONCLUSIONS: 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.

Psychopathological precursors of the onset of mood disorders in offspring of parents with and without mood disorders: results of a 13-year prospective cohort high-risk study.

BACKGROUND: There is still limited evidence from prospective high-risk research on the evolution of specific disorders that may emerge early in the development of mood disorders. Moreover, few studies have examined the specificity of mood disorder subtypes among offspring of parents with both major subtypes of mood disorders and controls based on prospective tracking across the transition from childhood to adulthood. Our specific objectives were to (a) identify differences in patterns of psychopathological precursors among youth with (hypo)mania compared to MDD and (b) examine whether these patterns differ by subtypes of parental mood disorders. METHODS: Our data stem from a prospective cohort study of 449 directly interviewed offspring (51% female, mean age 10.1 years at study intake) of 88 patients with BPD, 71 with MDD, 30 with substance use disorders and 60 medical controls. The mean duration of follow-up was 13.2 years with evaluations conducted every three years. RESULTS: Within the whole cohort of offspring, MDE (Hazard Ratio = 4.44; 95%CI: 2.19-9.02), CD (HR = 3.31;1.55-7.07) and DUD (HR = 2.54; 1.15-5.59) predicted the onset of (hypo)manic episodes, whereas MDD in offspring was predicted by SAD (HR = 1.53; 1.09-2.15), generalized anxiety (HR = 2.56; 1.05-6.24), and panic disorder (HR = 3.13; 1.06-9.23). The early predictors of (hypo)mania in the whole cohort were also significantly associated with the onset of (hypo)mania among the offspring of parents with BPD. CONCLUSIONS: The onset of mood disorders is frequently preceded by identifiable depressive episodes and nonmood disorders. These precursors differed by mood subtype in offspring. High-risk offspring with these precursors should be closely monitored to prevent the further development of MDD or conversion to BPD.

Effect of Ketamine on Rumination in Treatment-Resistant Depressive Patients.

BACKGROUND: A rapid antidepressant effect of ketamine has repeatedly been documented in the literature, and identifying clinical features associated with a better response to this treatment is currently an essential question. Considering the relationship between rumination and depression and the need to identify potential predictors of response to ketamine, we analyzed the effect of a single injection of ketamine 0.5 mg/kg on rumination in treatment-resistant depressive (TRD) patients and explored whether baseline ruminative style and early improvements of rumination would predict a greater antidepressant effect of ketamine. METHODS: Ten TRD outpatients who participated in a 4-week open study on the antidepressant effect of ketamine also completed the Ruminative Response Scale the day before, the day after, and a week after ketamine administration. RESULTS: We found that in our patients, a single rapid 1-minute intravenous injection of ketamine 0.5 mg/kg was efficacious in reducing rumination, but neither severity of rumination at baseline nor early improvements of rumination after ketamine injection predicted antidepressant response. CONCLUSIONS: Our preliminary data suggest that a single injection of ketamine 0.5 mg/kg can be efficacious in reducing rumination in TRD patients but rumination does not seem to be a useful clinical predictor of response to ketamine. Larger studies are necessary to confirm these results.

Self-Destigmatization Process? Experiences of Persons Living with Bipolar Disorder: A Qualitative Study.

This qualitative study investigated subjective experiences of self-stigmatization and self-destigmatization among people living with bipolar disorder (BD). We conducted in-depth interviews focusing on self-stigmatization and self-destigmatization with 22 individuals living with BD. The interview transcripts were thematically analyzed using a mixed inductive and deductive approach. Thirty-six codes were extracted and organized into six themes: language, behaviors, relationships, personal experience, identity, and healthcare. Each theme was characterized by an evolution process, and the codes were distributed in a step-by-step order as landmarks. The process begins with the experience of self-stigmatization, and develops toward self-destigmatization. This study presents a new six-dimension process called the "self-destigmatization process" (SDP), a personal and interrelational process that deconstructs self-stigmatization. Clinicians can use the landmarks of the process for clinical assessment and therapeutic interventions to increase recovery orientation.

[Light - darkness and bipolar disorder]. / Lumière ­ obscurité et trouble bipolaire.

Circadian rhythmicity generated by the biological clock structures the functioning of human beings over a period of almost 24 hours. This clock is entrained daily by internal and external cues among which light is the most powerful. Several disturbances, whether clinical or biological, observed in bipolar disorders are suggestive of a disruption of the circadian rhythm. Thus, treatments that modulate the biological clock have been developed. So far, the results of light therapy are not unanimous and invite us to better specify the treatment modalities. Dark therapy is a promising intervention that is still not much studied nowadays and therefore opens up great prospects for research in the future.

Le rythme circadien généré par l'horloge biologique structure le fonctionnement de l'être humain sur une période de presque 24 heures. Cette horloge est quotidiennement «â€…mise à l'heure ¼ par des synchronisateurs internes et externes parmi lesquels la lumière est la plus puissante. Plusieurs perturbations tant cliniques que biologiques observées chez les personnes souffrant d'un trouble bipolaire sont évocatrices d'un dérèglement du rythme circadien. Ainsi, des traitements permettant de moduler l'horloge biologique ont été développés. Actuellement, les résultats de la luminothérapie ne sont pas unanimes et cela nous invite à mieux préciser les modalités du traitement. La thérapie par l'obscurité est une intervention prometteuse, peu étudiée et ouvre donc de belles perspectives de recherche.

Investigating polygenic burden in age at disease onset in bipolar disorder: Findings from an international multicentric study.

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 [>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.

Increased Reactivity of the Mesolimbic Reward System after Ketamine Injection in Patients with Treatment-resistant Major Depressive Disorder.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: The antidepressant effect of ketamine is associated with increased activity in the reward circuitry of the brain and a suppression of circuitry that mediates perceptual processing of negative emotions. The duration of ketamine effect on these brain structures remains to be defined. WHAT THIS ARTICLE TELLS US THAT IS NEW: As expected, ketamine administration led to an improvement in mood and global vigilance. The improvement in mood was accompanied by an increased recruitment of the orbitofrontal cortex, ventral striatum, medial substantial nigra and ventral tegmental area, structures that are part of the reward circuitry.Responses in the mesolimbic structures (amygdala, medial substantial nigra and ventral tegmental area, orbitofrontal cortex) to negative stimuli were decreased after ketamine administration.The data are consistent with the premise that ketamine induces sustained changes in the mesolimbic neural circuits to reset pathological reward and emotional processing. BACKGROUND: Ketamine rapidly improves maladaptive mood states in major depressive disorder, and some of the neural substrates underlying this therapeutic effect have been identified. This study aimed to identify functional changes within neural networks that may underlie the impact of ketamine on both reward and emotional processing in patients with treatment-resistant major depression. METHODS: Ten adult patients with a Montgomery-Åsberg Depression Rating Scale score above 25 were enrolled to receive a single intravenous administration of ketamine (0.5 mg/kg). Patients' performance along with related neural network activations were analyzed in a game-like reward task and in an emotional judgment task using functional magnetic resonance imaging 1 day before and 1 and 7 days after ketamine administration. RESULTS: A significant correlation (R = 0.46, P = 0.03) between the improvement of depression scores and the enhanced reaction time for positive items was found in the game-like reward task 1 day after ketamine administration. This enhanced sensitivity for rewarded items was accompanied by increased activity of reward-related brain regions, including the orbitofrontal cortex, ventral striatum, and the ventral tegmental area, an effect that persisted up to 1 week after ketamine injection. In the emotional judgment task, it was found that ketamine rapidly modified local brain activities in response to emotionally negative, positive, or neutral stimuli in the amygdala, insula, anterior cingulate cortex, and in the ventral tegmental area. CONCLUSIONS: Single bolus ketamine administration rapidly triggers lasting changes in mesolimbic neural networks to improve pathologic reward and emotional processing in patients with major depressive disorder.

Psychiatric disorders among offspring of patients with Bipolar and Borderline Personality Disorder.

OBJECTIVE: As part of a larger study investigating biological risk factors for bipolar disorder (BD) and borderline personality disorder (BPD), we investigated the prevalence of psychiatric diagnoses presented by young BD or BPD offspring. With respect to the scarcity of studies interested in psychiatric disorders among BPD offspring, we have chosen to report these results despite the small sample size for a prevalence study. METHOD: We recruited 21 BD and 22 BPD offspring and 23 control subjects. All subjects were assessed with a structured interview. RESULTS: Our main finding suggests that BPD offspring present a higher rate of psychiatric disorders compared to BD offspring. Attention deficit and hyperactivity disorder was the most prevalent disorder. CONCLUSION: Our results contribute to the evidence that offspring of patients with BPD, are at high risk with regard to their mental health and deserve both more research and special attention at the clinical level.

Genome-wide association study of 40,000 individuals identifies two novel loci associated with bipolar disorder.

Bipolar disorder (BD) is a genetically complex mental illness characterized by severe oscillations of mood and behaviour. Genome-wide association studies (GWAS) have identified several risk loci that together account for a small portion of the heritability. To identify additional risk loci, we performed a two-stage meta-analysis of >9 million genetic variants in 9,784 bipolar disorder patients and 30,471 controls, the largest GWAS of BD to date. In this study, to increase power we used ∼2,000 lithium-treated cases with a long-term diagnosis of BD from the Consortium on Lithium Genetics, excess controls, and analytic methods optimized for markers on the X-chromosome. In addition to four known loci, results revealed genome-wide significant associations at two novel loci: an intergenic region on 9p21.3 (rs12553324, P = 5.87 × 10 - 9; odds ratio (OR) = 1.12) and markers within ERBB2 (rs2517959, P = 4.53 × 10 - 9; OR = 1.13). No significant X-chromosome associations were detected and X-linked markers explained very little BD heritability. The results add to a growing list of common autosomal variants involved in BD and illustrate the power of comparing well-characterized cases to an excess of controls in GWAS.

Efficacy and Safety of a Rapid Intravenous Injection of Ketamine 0.5 mg/kg in Treatment-Resistant Major Depression: An Open 4-Week Longitudinal Study.

BACKGROUND: Ketamine has been documented for its rapid antidepressant effects. However, optimal dose and delivery route have not yet been thoroughly investigated. The objectives of this study were to document the safety and test the antidepressant and antisuicidal effects of a single rapid 1-minute injection of ketamine 0.5 mg/kg in treatment-resistant depression (TRD). METHODS: Ten patients with TRD were included in an open, noncontrolled 4-week study and received a rapid intravenous dose of ketamine 0.5 mg/kg. Main outcome measure was the Montgomery-Åsberg Depression Rating Scale and suicidality was assessed using the Scale for Suicide Ideation. RESULTS: Rapid injection of ketamine elicited transient increase of blood pressure and altered states of consciousness in all patients and mild psychotomimetic effects in 4 patients, which all resolved without any intervention. Decrease of depression severity was observed from 40-minute postinjection until day 15. Eight patients became responders within 1 day and all were nonresponders after 4 weeks. The decrease of suicidal ideation was significant until day 7. Analysis indicated that higher severity of depression and anxiety at baseline predicted a larger Montgomery-Åsberg Depression Rating Scale decrease after 4 weeks. CONCLUSIONS: This study suggests that in well-controlled medical settings with adequate monitoring, a single rapid 1-minute injection of ketamine 0.5 mg/kg can be well tolerated and is efficacious in rapidly reducing depression symptoms and suicidal thoughts in outpatients with TRD. These findings are relevant to the practice of general clinical psychiatry and emergency departments were ketamine can have a place in acute management of TRD. Larger studies are necessary to confirm these results.

Screening for genotypic and phenotypic variations in CYP450 activity in patients with therapeutic problems in a psychiatric setting, a retrospective study.

OBJECTIVES: This retrospective study aimed to assess to what extent an adverse drug reaction (ADR), an abnormal therapeutic drug monitoring (TDM) or a non-response, was attributable to an abnormal cytochrome P450 activity in a psychiatric setting. METHOD: We collected the results of investigations performed in these situations related to psychotropic drugs between January 2005 and November 2014. Activities of different cytochrome P450 were assessed by genotyping and/or phenotyping. Two experienced clinical pharmacologists assessed independently the possible association between the event and the results of the investigations. RESULTS: One hundred and thirty eight clinical or biological situations had a complete assessment of all major metabolic pathways of the target drug. A majority of clinical or biological situations were observed with antidepressants (n=93, 67.4%), followed by antipsychotics (n=28, 20.3%), benzodiazepines and hypnotics (n=13, 9.4%), and psychostimulants (n=4, 2.9%). Genotype and/or phenotype determination was mainly performed because of ADRs (n=68, 49.3%) or non-response (n=46, 33.3%). Inter-rate reliability of the scoring system between the pharmacologists was excellent (kappa=0.94). The probability of an association between ADR, TDM or non-response and metabolic status was rated as intermediate to high in 34.7% of all cases, with proportions of 30.4% and 36.7%, for non-response and ADR respectively. CONCLUSION: When indicated by clinical pharmacologists, ADR, TDM or non-response may be attributable to a variation of the metabolic status with an intermediate to high probability in 34.7% of patients, based on the congruent assessment made by two clinical pharmacologists. Further studies assessing the clinical relevance of prospective explorations and clarifying the appropriate method according to the clinical context are needed.

The Lausanne-Geneva cohort study of offspring of parents with mood disorders: methodology, findings, current sample characteristics, and perspectives.

PURPOSE: Studies focusing on the offspring of affected parents utilize the well-established familial aggregation of mood disorders as a powerful tool for the identification of risk factors, early clinical manifestations, and prodromes of mood disorders in these offspring. The major goals of the Lausanne-Geneva mood cohort study are to: (1) assess the familial aggregation of bipolar and unipolar mood disorders; (2) prospectively identify risk factors for mood disorders as well as their early signs and prodromes; (3) identify their endophenotypes including cognitive features, alterations in brain structure, HPA-axis dysregulation, and abnormalities of the circadian rhythm of activity. METHODS: Probands with bipolar disorders, major depressive disorder, and controls with at least one child aged from 4 to 17.9 years at study intake, their offspring, as well as their spouses are invited to take part in follow-up assessments at predetermined ages of the offspring. Direct semi-structured diagnostic interviews have been used for all participants. Probands, spouses, and adult offspring also undergo neurocognitive testing, anthropomorphic measures and biochemical exams, structural Magnetic Resonance Imaging, as well as objective assessments of physical activity using accelerometers in combination with ecological momentary assessments. RESULTS: Currently, our study has up to seven follow-up assessments extending over a period of 20 years. There are 214 probands and 389 offspring with one direct interview before age 18 as well as a second assessment over follow-up. Data on 236 co-parents are also available from whom 55% have been directly interviewed. First publications support the specificity of the familial aggregation of BPD and the strong influence of an early onset of the parental BPD, which amplifies the risk of developing this disorder in offspring. CONCLUSIONS: Information from clinical, biological, cognitive, and behavioral measures, based on contemporary knowledge, should further enhance our understanding of mood disorder psychopathology, its consequences, and underlying mechanisms.

Association of genetic risk scores with body mass index in Swiss psychiatric cohorts.

OBJECTIVE: Weight gain is associated with psychiatric disorders and/or with psychotropic drug treatments. We analyzed in three psychiatric cohorts under psychotropic treatment the association of weighted genetic risk scores (w-GRSs) with BMI by integrating BMI-related polymorphisms from the candidate-gene approach and Genome-Wide Association Studies (GWAS). MATERIALS AND METHODS: w-GRS of 32 polymorphisms associated previously with BMI in general population GWAS and 20 polymorphisms associated with antipsychotics-induced weight gain were investigated in three independent psychiatric samples. RESULTS: w-GRS of 32 polymorphisms were significantly associated with BMI in the psychiatric sample 1 (n=425) and were replicated in another sample (n=177). Those at the percentile 95 (p95) of the score had 2.26 and 2.99 kg/m(2) higher predicted BMI compared with individuals at the percentile 5 (p5) in sample 1 and in sample 3 (P=0.009 and 0.04, respectively). When combining all samples together (n=750), a significant difference of 1.89 kg/m(2) predicted BMI was found between p95 and p5 individuals at 12 months of treatment. Stronger associations were found among men (difference: 2.91 kg/m(2) of predicted BMI between p95 and p5, P=0.0002), whereas no association was found among women. w-GRS of 20 polymorphisms was not associated with BMI. The w-GRS of 52 polymorphisms and the clinical variables (age, sex, treatment) explained 1.99 and 3.15%, respectively, of BMI variability. CONCLUSION: The present study replicated in psychiatric cohorts previously identified BMI risk variants obtained in GWAS analyses from population-based samples. Sex-specific analysis should be considered in further analysis.