Differential contributions of circadian clock genes to cell survival in bipolar disorder patient derived neuronal progenitor cells distinguishes lithium responders and non-responders.

Bipolar disorder (BD) is characterized by disrupted circadian rhythms and neuronal loss. Lithium is neuroprotective and used to treat BD, but outcomes are variable. Past research identified that circadian rhythms in BD patient neurons are associated with lithium response (Li-R) or non-response (Li-NR). However, the underlying cellular mechanisms remain unknown. To study interactions among circadian clock genes and cell survival, and their role in BD and predicting lithium response, we tested selected genes (PER1, BMAL1 and REV-ERBα) and small molecule modulators of ROR/REV-ERB nuclear receptors in models of cell survival using mouse neurons and stem-cell derived neuronal progenitor cells (NPC) from BD patients and controls. In apoptosis assays using staurosporine (STS), lithium was neuroprotective. Knockdown of PER1, BMAL1 and REV-ERBα modified cell survival across models. In NPCs, reduced expression of PER1 and BMAL1 led to more extensive cell death in Li-NR vs. Li-R. Reduced REV-ERBα expression caused more extensive cell death in BD vs. control NPCs, without distinguishing Li-R and Li-NR. In IMHN, The REV-ERB agonist GSK4112 had strong effects on circadian rhythm amplitude, and was neuroprotective in mouse neurons and control NPCs, but not in BD NPCs. Expression of cell survival genes following STS and GSK4112 treatments revealed BD-associated, and Li-R associated differences in expression profiles. We conclude that the neuroprotective response to lithium is similar in NPCs from Li-R and Li-NR. However, knockdown of circadian clock genes or stimulation of REV-ERBs reveal distinct contributions to cell death in BD patient NPCs, some of which distinguish Li-R and Li-NR.

Contributions of circadian clock genes to cell survival in fibroblast models of lithium-responsive bipolar disorder.

Bipolar disorder (BD) is characterized by mood episodes, disrupted circadian rhythms and gray matter reduction in the brain. Lithium is an effective pharmacotherapy for BD, but not all patients respond to treatment. Lithium has neuroprotective properties and beneficial effects on circadian rhythms that may distinguish lithium responders (Li-R) from non-responders (Li-NR). The circadian clock regulates molecular pathways involved in apoptosis and cell survival, but how this overlap impacts BD and/or lithium responsiveness is unknown. In primary fibroblasts from Li-R/Li-NR BD patients and controls, we found patterns of co-expression among circadian clock and cell survival genes that distinguished BD vs. control, and Li-R vs. Li-NR cells. In cellular models of apoptosis using staurosporine (STS), lithium preferentially protected fibroblasts against apoptosis in BD vs. control samples, regardless of Li-R/Li-NR status. When examining the effects of lithium treatment of cells in vitro, caspase activation by lithium correlated with period alteration, but the relationship differed in control, Li-R and Li-NR samples. Knockdown of Per1 and Per3 in mouse fibroblasts altered caspase activity, cell death and circadian rhythms in an opposite manner. In BD cells, genetic variation in PER1 and PER3 predicted sensitivity to apoptosis in a manner consistent with knockdown studies. We conclude that distinct patterns of coordination between circadian clock and cell survival genes in BD may help predict lithium response.

Focal adhesion is associated with lithium response in bipolar disorder: evidence from a network-based multi-omics analysis.

Lithium (Li) is one of the most effective drugs for treating bipolar disorder (BD), however, there is presently no way to predict response to guide treatment. The aim of this study is to identify functional genes and pathways that distinguish BD Li responders (LR) from BD Li non-responders (NR). An initial Pharmacogenomics of Bipolar Disorder study (PGBD) GWAS of lithium response did not provide any significant results. As a result, we then employed network-based integrative analysis of transcriptomic and genomic data. In transcriptomic study of iPSC-derived neurons, 41 significantly differentially expressed (DE) genes were identified in LR vs NR regardless of lithium exposure. In the PGBD, post-GWAS gene prioritization using the GWA-boosting (GWAB) approach identified 1119 candidate genes. Following DE-derived network propagation, there was a highly significant overlap of genes between the top 500- and top 2000-proximal gene networks and the GWAB gene list (Phypergeometric = 1.28E-09 and 4.10E-18, respectively). Functional enrichment analyses of the top 500 proximal network genes identified focal adhesion and the extracellular matrix (ECM) as the most significant functions. Our findings suggest that the difference between LR and NR was a much greater effect than that of lithium. The direct impact of dysregulation of focal adhesion on axon guidance and neuronal circuits could underpin mechanisms of response to lithium, as well as underlying BD. It also highlights the power of integrative multi-omics analysis of transcriptomic and genomic profiling to gain molecular insights into lithium response in BD.

Alcohol intake in relation to suicidal ideation and behavior among university students.

ObjectiveHeavy alcohol use has been clearly linked to risk for suicidal behaviors and is also prevalent on many American college campuses. This report uses a large sample of college students to explore relationships between alcohol use, depressive symptoms, and suicidality. Methods: A brief suicide screen was completed by 40,335 university students at four pariticipating sites. Assessments quantified recent depressive symptoms, alcohol use, suicidal ideation, and suicide attempts. Results: Problems from alcohol use were consistently associated with suicidal thoughts and attempts in the previous month, and in the previous year, but the quantity of alcohol used was not. Alcohol related problems exerted effects on the likelihood of both suicide ideation and attempts beyond those explained by their relationship with depressive symptoms. Conclusions: Screens for individuals at increased risk for suicidal ideation and behavior should emphasize alcohol-related problems over quantification of alcohol intake.

A validation study of PHQ-9 suicide item with the Columbia Suicide Severity Rating Scale in outpatients with mood disorders at National Network of Depression Centers.

BACKGROUND: In the United States, suicide is one of the serious public health problems and a major cause of death. Several researchers and clinical settings use the patient health questionnaires (PHQ-9) to gauge depression and psychological distress among adults and to predict suicide and death. This study aimed to assess the sensitivity, specificity, and predictive potential of suicide Q9 of the PHQ-9 compared to the Columbia-suicide severity rating scale (C-SSRS). METHODS: Adults aged 19 or older, identified with a primary mood disorder diagnosis during their initial clinic visit between 2012 and 2020 from the National Network of Depression Centers, were included in the study. The accuracy of the PHQ-9 suicide item was compared with the gold standard, the C-SSRS. RESULTS: Out of 2677 study participants, 31.6 % (n = 846) and 11.65 % (n = 312) had positive responses to the PHQ-9 suicide item and C-SSRS response, respectively. The sensitivity of the PHQ-9 compared to the C-SSR was 74.7 % (95%CI: 69.6 %-79.2 %), specificity 74.1 % (95%CI: 72.3 %-75.8 %), positive predictive value 27.5 % (95%CI: 24.6 %-30.6 %), and negative predictive value 95.7 % (95%CI: 94.7 %-96.5 %). The secondary analysis results showed better validity results of the PHQ-9 suicide item when compared to the suicide ideation item of the C-SSRS. LIMITATIONS: This study is among mood disorder patients so additional research would be necessary among populations with different conditions. CONCLUSION: For initial suicide screening, the PHQ-9 suicide item would over identify patients as at risk for suicide and the C-SSRS should be used mood disorder clinics to identify suicide risk.

Suicidality and Alcohol Use as Predictors of Future Suicidal Behavior in College Students.

AIMS: There has been a marked increase in suicide fatalities among college-age students in recent years. Moreover, heavy alcohol use, a well-known risk factor for suicide, is present on most campuses. Yet, no prospective studies have examined alcohol use patterns among college students as predictors of suicidal behaviors. METHODS: Online of 40,335 students at four universities took place at the beginning of four academic years, 2015-2018. Of these, 2296 met criteria for an increased risk of suicidal behavior and completed 1- and/or 6-month follow-up evaluation(s). Baseline assessments included the Alcohol Use Disorders Identification Test to quantify alcohol consumption and resulting problems, and measures of depression, suicidal ideation and suicidal behavior. RESULTS: Suicide attempts during follow-up were reported by 35 (1.5%) of high-risk students. Regression analyses indicated that baseline severity of alcohol use consequences, but not amount of alcohol consumption, was associated with greater odds of a follow-up suicide attempt after controlling for baseline suicidal ideation, functional impairment and history of suicide attempts. CONCLUSIONS: Among college students at elevated risk for suicide, the severity of alcohol-related consequences was a significant predictor of future suicide attempts. Alcohol consumption was not a significant predictor, suggesting that the amount students drink is less of a concern for suicidal behavior than are the problems (e.g. failing to meet expectations, experiencing blackouts) associated with drinking.

Suicide risk profiles and barriers to professional help-seeking among college students with elevated risk for suicide.

Suicide is the second leading cause of death among college students, yet many students with elevated suicide risk do not seek professional help. This study identified suicide risk profiles among college students and examined these in relation to students' perceived barriers to professional help-seeking. Data were obtained from college students (n = 1689) identified to be at elevated risk for suicide based at four US universities. Latent class analysis was performed to determine risk profiles, followed by examinations of differences in help-seeking barriers by profile groupings. Results revealed three student groupings: (1) moderate internalizing and externalizing symptoms (with low alcohol misuse), (2) highest internalizing and externalizing symptoms (with highest social disconnection), and (3) lowest internalizing symptoms and low externalizing (with highest social connection and alcohol misuse). Group 1 included the youngest and most racially and sexually diverse students, Group 2 endorsed the most help-seeking barriers, and Group 3 endorsed the fewest barriers. Group 2 is especially concerning, considering the severe clinical characteristics, high number of barriers, and low connectedness to others for potential support. Understanding these differences across risk and barrier profiles is an important step towards developing tailored approaches to increase mental health care in college populations.

Anxiety symptoms and suicidal thoughts and behaviors among patients with mood disorders.

BACKGROUND: Though the association between anxiety disorders and suicidal behavior is well-described, the impact of anxiety symptoms on suicidal thoughts and behaviors (STB) across different mood disorders is still unclear. METHODS: We performed a registry-based retrospective study utilizing outcome measure data collected by the National Network of Depression Centers (NNDC), a nationwide nonprofit consortium of 26 leading clinical and academic member centers in the United States. The sample consisted of 2607 outpatients with mood disorders (major depressive disorder or bipolar disorders). Demographic and clinical variables were compared based on the presence or absence of STB and severity of anxiety symptoms (minimal, mild, moderate, and severe). Univariate and multivariable logistic regressions were conducted to examine the correlations of STB, considering multicollinearity. RESULTS: Patients with mild, moderate, and severe anxiety symptoms had higher odds of STB than those with minimal symptoms. Gender, marital status, age, and depressive symptoms were other strong predictors of STB. There was no difference in the odds of STB between patients with major depressive disorder (MDD) and those with bipolar disorders (BD). However, the odds of suicidal ideation were slightly lower among patients with BD than those with MDD. LIMITATIONS: Our sample was comprised only of outpatients, limiting the generalization of our findings. Other limitations include the lack of structured interviews for diagnostic characterization of the patients and the utilization of data on anxiety and mood obtained solely through self-report scales. CONCLUSIONS: We found a cross-sectional association between the severity of anxiety symptoms and STB among patients with mood disorders. This study demonstrates the need for a suicide risk assessment in patients with mood disorders reporting anxiety symptoms.

Engagement With Personalized Feedback for Emotional Distress Among College Students at Elevated Suicide Risk.

Depression and suicidal ideation have substantially increased among college students, yet many students with clinically significant symptoms do not perceive their distress as warranting mental health services. Personalized feedback (PF) interventions deliver objective data, often electronically, comparing an individual's reported symptoms or behaviors to a group norm. Several studies have shown promise for PF interventions in the context of mood and depression, yet little is known regarding how, and for whom, mood-focused PF interventions might be best deployed. The primary aim of this study was to examine the sociodemographic, clinical, and treatment-seeking factors associated with reviewing PF reports on emotional distress among college students (N = 1,673) screening positive for elevated suicide risk and not receiving mental health treatment. Results indicated that PF engagement was greatest among those with higher depression scores, and those reporting privacy/stigma concerns as barriers to treatment. Sexual minority students were more likely to review their PF than heterosexual students. Taken together, PF interventions may be a useful tool for engaging those with greater clinical acuity, and those hesitant to seek in-person care. Further research is warranted to examine the circumstances in which PF interventions might be used in isolation, or as part of a multitiered intervention strategy.

Electronic bridge to mental health for college students: A randomized controlled intervention trial.

OBJECTIVE: Suicide is the second leading cause of death among college students in the United States, and the percentage of students reporting suicidal thoughts is increasing. Nevertheless, many students at risk do not seek mental health (MH) services. This randomized controlled trial (RCT) examined the efficacy of Electronic Bridge to Mental Health for College Students (eBridge) for increasing at-risk students' linkage to MH services. METHOD: Students from four universities were recruited via email; 40,347 (22.6%) completed the online suicide risk screen; and 3,363 (8.3%) met criteria for randomization based on suicide risk factors and lack of current treatment (62.2% female, 35.0% male, 2.8% transgender/nonbinary; 73.2% White, 7.0% Black, 19.9% Asian, 11.7% other; 12.4% Hispanic, 76.2% undergraduate). These students were randomized to eBridge [personalized feedback (PF) with option of online counseling] or Control (PF). The primary outcome was linkage to MH services within 6 months. RESULTS: Among students assigned to eBridge, 355 students (21.0%) posted ≥1 message, and 168 (10.0%) posted ≥2 messages to the counselor. In intent-to-treat analyses, there was no eBridge effect on obtaining MH services. However, within the eBridge group, students who posted ≥1 message were significantly more likely to link to MH services. CONCLUSIONS: eBridge shows promise for reaching a relatively small subset of college students at risk for suicide; however, engagement in eBridge was low. This study underscores the urgent need for more effective strategies to engage young adults in online mental health interventions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Correction of depression-associated circadian rhythm abnormalities is associated with lithium response in bipolar disorder.

BACKGROUND: Bipolar disorder (BD) is characterized by episodes of depression and mania and disrupted circadian rhythms. Lithium is an effective therapy for BD, but only 30%-40% of patients are fully responsive. Preclinical models show that lithium alters circadian rhythms. However, it is unknown if the circadian rhythm effects of lithium are essential to its therapeutic properties. METHODS: In secondary analyses of a multi-center, prospective, trial of lithium for BD, we examined the relationship between circadian rhythms and therapeutic response to lithium. Using standardized instruments, we measured morningness, diurnal changes in mood, sleep, and energy (circadian rhythm disturbances) in a cross-sectional study of 386 BD subjects with varying lithium exposure histories. Next, we tracked symptoms of depression and mania prospectively over 12 weeks in a subset of 88 BD patients initiating treatment with lithium. Total, circadian, and affective mood symptoms were scored separately and analyzed. RESULTS: Subjects with no prior lithium exposure had the most circadian disruption, while patients stable on lithium monotherapy had the least. Patients who were stable on lithium with another drug or unstable on lithium showed intermediate levels of disruption. Treatment with lithium for 12 weeks yielded significant reductions in total and affective depression symptoms. Lithium responders (Li-Rs) showed improvement in circadian symptoms of depression, but non-responders did not. There was no difference between Li-Rs and nonresponders in affective, circadian, or total symptoms of mania. CONCLUSIONS: Exposure to lithium is associated with reduced circadian disruption. Lithium response at 12 weeks was selectively associated with the reduction of circadian depressive symptoms. We conclude that stabilization of circadian rhythms may be an important feature of lithium's therapeutic effects. CLINICAL TRIALS REGISTRY: NCT0127253.

Symptoms of mania and anxiety do not contribute to suicidal ideation or behavior in the presence of bipolar depression.

Bipolar disorder is typified by episodes of manic/hypomanic and depressive symptoms, either distinctly or concurrently as mixed symptoms. While depressive symptoms are the major driver of risk, it is unclear whether specific combinations of manic and anxiety symptoms contribute differentially to suicidal ideation and behavior in individuals with bipolar disorder during a depressive state. This study uses a quantitative application of Rothman's theoretical framework of causation, or 'causal pies' model. Data were obtained from the National Network of Depression Centers Mood Outcomes Program for 1028 visits from 626 individuals with bipolar disorder with current moderate-to-severe depressive symptoms, operationalized as a Patient Health Questionnaire-8 (PHQ-8) score ≥10. Mania symptoms were captured using the Altman Self-Rating Mania scale (ASRM) and anxiety symptoms were captured using the Generalized Anxiety Disorder-7 scale (GAD-7). The outcome of suicidal ideation or behavior was captured using the Columbia Suicide Severity Rating Scale (C-SSRS). In this cohort of individuals with bipolar disorder and at least moderate depressive symptoms, we found no increased risk of suicidal ideation or behavior attributable to manic and anxiety symptom clusters in individuals with bipolar disorder during depressive state. A small amount (4%) of risk was attributable to having severe depressive symptoms. These findings, however, may be influenced by limitations in sample size and measurement instruments. Future studies would benefit from larger samples and more rigorous assessments, including clinician-rated measures.

Effects of somatic treatments on suicidal ideation and completed suicides.

OBJECTIVE: This work was undertaken to define and characterize the role of currently available somatic treatments in psychiatry in either increasing or reducing the risk for suicide. METHODS: Members of the Suicide Prevention Task Group of the National Network of Depression Centers performed a literature review of somatic treatments known to increase or reduce the risk for suicide. The reviews ventured to include all relevant information about the risk for both suicide ideation and completed suicides. RESULTS: Lithium and clozapine are the only two somatic treatments that have high-quality data documenting their antisuicide effects in mood disorders and schizophrenia, respectively. Lithium discontinuation is also associated with increased suicide risk. Ketamine and esketamine may have a small, but immediate, antisuicide effect. Despite the recent Food and Drug Administration approval of esketamine use in depressed suicidal patients, the small disproportional overrepresentation of suicide in subjects who had received esketamine versus placebo (3 vs. 0 among > 3500 subjects) requires ongoing evaluation. The purported antisuicide effect of electroconvulsive therapy is based on low-quality data. The effect of antidepressants is not at all clear. There appears to be direct evidence for antidepressants increasing suicidal ideation and the risk for suicide over the short-term in young people, but indirect (low quality) evidence that antidepressants reduce suicide risk over the long term. CONCLUSIONS: Clinicians have an expanding pharmacopeia to address suicide potential in their patients. Some of the agents with documented antisuicide effects may also increase suicidality under specific circumstances.

Targeting the coronavirus nucleocapsid protein through GSK-3 inhibition.

The coronaviruses responsible for severe acute respiratory syndrome (SARS-CoV), COVID-19 (SARS-CoV-2), Middle East respiratory syndrome-CoV, and other coronavirus infections express a nucleocapsid protein (N) that is essential for viral replication, transcription, and virion assembly. Phosphorylation of N from SARS-CoV by glycogen synthase kinase 3 (GSK-3) is required for its function and inhibition of GSK-3 with lithium impairs N phosphorylation, viral transcription, and replication. Here we report that the SARS-CoV-2 N protein contains GSK-3 consensus sequences and that this motif is conserved in diverse coronaviruses, raising the possibility that SARS-CoV-2 may be sensitive to GSK-3 inhibitors, including lithium. We conducted a retrospective analysis of lithium use in patients from three major health systems who were PCR-tested for SARS-CoV-2. We found that patients taking lithium have a significantly reduced risk of COVID-19 (odds ratio = 0.51 [0.35-0.74], P = 0.005). We also show that the SARS-CoV-2 N protein is phosphorylated by GSK-3. Knockout of GSK3A and GSK3B demonstrates that GSK-3 is essential for N phosphorylation. Alternative GSK-3 inhibitors block N phosphorylation and impair replication in SARS-CoV-2 infected lung epithelial cells in a cell-type-dependent manner. Targeting GSK-3 may therefore provide an approach to treat COVID-19 and future coronavirus outbreaks.

Developing an IV Ketamine Clinic for Treatment-Resistant Depression: a Primer.

The efficacy of subanesthetic intravenous ketamine for treatment resistant depression (TRD) has spurred a growth of clinics nationwide that provide this service. Ketamine is an FDA-approved drug as an anesthetic but remains unapproved for psychiatric indications, and this status raises a number of short- and long-term safety and efficacy concerns that need to be addressed when implementing and developing this type of clinic. Using a framework of systems, provider, and patient domains, we provide a review of the key challenges in providing ketamine infusions and suggest potential approaches. Under systems issues, we highlight broad stakeholder engagement involving cross-departmental and multidisciplinary considerations, business case development, and delineation of administrative standard operating procedures. In the provider domain, we highlight specific roles for different treatment team members as well as suggested training requirements. In the patient domain, we identify a variety of standard operating procedures involving initial patient assessment parameters, ketamine dosing and administration guidelines, and safety monitoring procedures. Together, this review provides key considerations for developing a ketamine clinic for depression, in an effort to meet the pressing demand for this novel treatment option while helping to ensure its safe implementation.

Clinical predictors of non-response to lithium treatment in the Pharmacogenomics of Bipolar Disorder (PGBD) study.

BACKGROUND: Lithium is regarded as a first-line treatment for bipolar disorder (BD), but partial response and non-response commonly occurs. There exists a need to identify lithium non-responders prior to initiating treatment. The Pharmacogenomics of Bipolar Disorder (PGBD) Study was designed to identify predictors of lithium response. METHODS: The PGBD Study was an eleven site prospective trial of lithium treatment in bipolar I disorder. Subjects were stabilized on lithium monotherapy over 4 months and gradually discontinued from all other psychotropic medications. After ensuring a sustained clinical remission (defined by a score of ≤3 on the CGI for 4 weeks) had been achieved, subjects were followed for up to 2 years to monitor clinical response. Cox proportional hazard models were used to examine the relationship between clinical measures and time until failure to remit or relapse. RESULTS: A total of 345 individuals were enrolled into the study and included in the analysis. Of these, 101 subjects failed to remit or relapsed, 88 achieved remission and continued to study completion, and 156 were terminated from the study for other reasons. Significant clinical predictors of treatment failure (p < 0.05) included baseline anxiety symptoms, functional impairments, negative life events and lifetime clinical features such as a history of migraine, suicidal ideation/attempts, and mixed episodes, as well as a chronic course of illness. CONCLUSIONS: In this PGBD Study of lithium response, several clinical features were found to be associated with failure to respond to lithium. Future validation is needed to confirm these clinical predictors of treatment failure and their use clinically to distinguish who will do well on lithium before starting pharmacotherapy.

Targeting the Coronavirus Nucleocapsid Protein through GSK-3 Inhibition.

The coronaviruses responsible for severe acute respiratory syndrome (SARS-CoV), COVID-19 (SARS-CoV-2), Middle East respiratory syndrome (MERS-CoV), and other coronavirus infections express a nucleocapsid protein (N) that is essential for viral replication, transcription, and virion assembly. Phosphorylation of N from SARS-CoV by glycogen synthase kinase 3 (GSK-3) is required for its function and inhibition of GSK-3 with lithium impairs N phosphorylation, viral transcription, and replication. Here we report that the SARS-CoV-2 N protein contains GSK-3 consensus sequences and that this motif is conserved in diverse coronaviruses, raising the possibility that SARS-CoV-2 may be sensitive to GSK-3 inhibitors including lithium. We conducted a retrospective analysis of lithium use in patients from three major health systems who were PCR tested for SARS-CoV-2. We found that patients taking lithium have a significantly reduced risk of COVID-19 (odds ratio = 0.51 [0.35 - 0.74], p = 0.005). We also show that the SARS-CoV-2 N protein is phosphorylated by GSK-3. Knockout of GSK3A and GSK3B demonstrates that GSK-3 is essential for N phosphorylation. Alternative GSK-3 inhibitors block N phosphorylation and impair replication in SARS-CoV-2 infected lung epithelial cells in a cell-type dependent manner. Targeting GSK-3 may therefore provide a new approach to treat COVID-19 and future coronavirus outbreaks. SIGNIFICANCE: COVID-19 is taking a major toll on personal health, healthcare systems, and the global economy. With three betacoronavirus epidemics in less than 20 years, there is an urgent need for therapies to combat new and existing coronavirus outbreaks. Our analysis of clinical data from over 300,000 patients in three major health systems demonstrates a 50% reduced risk of COVID-19 in patients taking lithium, a direct inhibitor of glycogen synthase kinase-3 (GSK-3). We further show that GSK-3 is essential for phosphorylation of the SARS-CoV-2 nucleocapsid protein and that GSK-3 inhibition blocks SARS-CoV-2 infection in human lung epithelial cells. These findings suggest an antiviral strategy for COVID-19 and new coronaviruses that may arise in the future.

Circadian rhythms in bipolar disorder patient-derived neurons predict lithium response: preliminary studies.

Bipolar disorder (BD) is a neuropsychiatric illness defined by recurrent episodes of mania/hypomania, depression and circadian rhythm abnormalities. Lithium is an effective drug for BD, but 30-40% of patients fail to respond adequately to treatment. Previous work has demonstrated that lithium affects the expression of "clock genes" and that lithium responders (Li-R) can be distinguished from non-responders (Li-NR) by differences in circadian rhythms. However, circadian rhythms have not been evaluated in BD patient neurons from Li-R and Li-NR. We used induced pluripotent stem cells (iPSCs) to culture neuronal precursor cells (NPC) and glutamatergic neurons from BD patients characterized for lithium responsiveness and matched controls. We identified strong circadian rhythms in Per2-luc expression in NPCs and neurons from controls and Li-R, but NPC rhythms in Li-R had a shorter circadian period. Li-NR rhythms were low amplitude and profoundly weakened. In NPCs and neurons, expression of PER2 was higher in both BD groups compared to controls. In neurons, PER2 protein levels were higher in BD than controls, especially in Li-NR samples. In single cells, NPC and neuron rhythms in both BD groups were desynchronized compared to controls. Lithium lengthened period in Li-R and control neurons but failed to alter rhythms in Li-NR. In contrast, temperature entrainment increased amplitude across all groups, and partly restored rhythms in Li-NR neurons. We conclude that neuronal circadian rhythm abnormalities are present in BD and most pronounced in Li-NR. Rhythm deficits in BD may be partly reversible through stimulation of entrainment pathways.

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.