Publications by authors named "Nick Craddock"

203 Publications

Investigating rare pathogenic/likely pathogenic exonic variation in bipolar disorder.

Mol Psychiatry 2021 Jan 22. Epub 2021 Jan 22.

HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA.

Bipolar disorder (BD) is a serious mental illness with substantial common variant heritability. However, the role of rare coding variation in BD is not well established. We examined the protein-coding (exonic) sequences of 3,987 unrelated individuals with BD and 5,322 controls of predominantly European ancestry across four cohorts from the Bipolar Sequencing Consortium (BSC). We assessed the burden of rare, protein-altering, single nucleotide variants classified as pathogenic or likely pathogenic (P-LP) both exome-wide and within several groups of genes with phenotypic or biologic plausibility in BD. While we observed an increased burden of rare coding P-LP variants within 165 genes identified as BD GWAS regions in 3,987 BD cases (meta-analysis OR = 1.9, 95% CI = 1.3-2.8, one-sided p = 6.0 × 10), this enrichment did not replicate in an additional 9,929 BD cases and 14,018 controls (OR = 0.9, one-side p = 0.70). Although BD shares common variant heritability with schizophrenia, in the BSC sample we did not observe a significant enrichment of P-LP variants in SCZ GWAS genes, in two classes of neuronal synaptic genes (RBFOX2 and FMRP) associated with SCZ or in loss-of-function intolerant genes. In this study, the largest analysis of exonic variation in BD, individuals with BD do not carry a replicable enrichment of rare P-LP variants across the exome or in any of several groups of genes with biologic plausibility. Moreover, despite a strong shared susceptibility between BD and SCZ through common genetic variation, we do not observe an association between BD risk and rare P-LP coding variants in genes known to modulate risk for SCZ.
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http://dx.doi.org/10.1038/s41380-020-01006-9DOI Listing
January 2021

Have I argued with my family this week?": What questions do those with lived experience choose to monitor their bipolar disorder?

J Affect Disord 2021 02 11;281:918-925. Epub 2020 Nov 11.

Psychological Medicine, University of Worcester, Henwick Grove, Worcester, WR2 6AJ, UK. Electronic address:

Background: Electronic self-report mood monitoring tools for individuals with bipolar disorder (BD) are rapidly emerging and predominately employ predefined symptom-based questions. Allowing individuals to additionally choose what they monitor in relation to their BD offers the unique opportunity to capture and gain a deeper insight into patient priorities in this context.

Methods: In addition to monitoring mood symptoms with two standardised self-rated questionnaires, 308 individuals with BD participating in the Bipolar Disorder Research Network True Colours electronic mood-monitoring tool for research chose to create and complete additional personalised questions. A content analysis approach was used to analyse the content of these questions.

Results: 35 categories were created based on the personalised questions with the most common being physical activity and exercise, anxiety and panic, sleep and coping/stress levels. The categories were grouped into six overarching themes 1) mental health; 2) behaviour and level of functioning; 3) physical wellbeing; 4) health behaviours; 5) active self-management; and, 6) interpersonal.

Limitations: The average age of the sample was around 50 years meaning our findings may not be generalisable to younger individuals with BD.

Conclusions: Aspects of BD important to patients in relation to longitudinal monitoring extend well beyond mood symptoms, highlighting the limitations of solely relying on standardised questions/mood rating scales based on symptoms primarily used for diagnosis. Additional symptoms and aspects of life not necessarily useful diagnostically for BD may be more important for individuals themselves to monitor and have more meaning in capturing their own experience of changes in BD severity.
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http://dx.doi.org/10.1016/j.jad.2020.11.034DOI Listing
February 2021

The influence of borderline personality traits on clinical outcomes in bipolar disorder.

Bipolar Disord 2020 Jul 12. Epub 2020 Jul 12.

Psychological Medicine, University of Worcester, Worcester, UK.

Objectives: Systematic reviews suggest comorbid borderline personality disorder is present in approximately 20% of individuals who have bipolar disorder, but current diagnostic systems demonstrate a move towards dimensional rather than categorical approaches to classifying personality pathology. We aimed to examine the presence and severity of borderline personality traits in bipolar I and bipolar II disorder, and to explore associations between the presence/severity of borderline personality traits and clinical outcomes in bipolar disorder.

Methods: Borderline personality traits were measured in 1447 individuals with DSM-IV bipolar disorder (1008 bipolar I disorder and 439 bipolar II disorder) using the Borderline Evaluation of Severity over Time (BEST) questionnaire. Lifetime clinical outcomes were assessed via Schedules for Clinical Assessment in Neuropsychiatry (SCAN) semi-structured interview and clinical case notes.

Results: Borderline personality traits were common in both bipolar disorder groups, with 86.2% participants reporting at least one trait. These included traits that overlap with (eg mood instability) and those that are distinct from the symptoms of bipolar disorder (eg fear of abandonment). Borderline personality traits were significantly more frequent and more severe in bipolar II disorder compared to bipolar I disorder. More severe borderline traits, and even the presence of a single borderline personality trait, were significantly associated with younger age of bipolar disorder onset and higher prevalence of lifetime alcohol misuse in both bipolar disorder groups.

Conclusions: The presence of comorbid borderline personality traits should be considered in the management of all patients with bipolar disorder irrespective of whether criteria for a categorical borderline personality disorder diagnosis are met.
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http://dx.doi.org/10.1111/bdi.12978DOI Listing
July 2020

Patterns and clinical correlates of lifetime alcohol consumption in women and men with bipolar disorder: Findings from the UK Bipolar Disorder Research Network.

Bipolar Disord 2020 11 13;22(7):731-738. Epub 2020 Apr 13.

Psychological Medicine, University of Worcester, Worcester, UK.

Objectives: Despite previous literature on comorbid alcohol use disorders (AUDs) in bipolar disorder (BD), little is known about patterns of alcohol use more widely in this population. We have examined lifetime heaviest average weekly alcohol consumption levels in a large well-characterised UK sample including lifetime clinical correlates of increasing levels of alcohol use.

Methods: Participants were 1203 women and 673 men with bipolar I disorder interviewed by semi-structured interview who had consumed alcohol regularly at any point in their life.

Results: Over half of both women (52.3%) and men (73.6%) had regularly consumed over double the current UK recommended guideline for alcohol consumption. In women and men increasing levels of lifetime alcohol consumption were significantly associated with the presence of suicide attempts (women: OR 1.82, P < .001; men: OR 1.48, P = .005) and rapid cycling (women: OR 1.89, P < .001; men: OR 1.88, P < .001). In women only, increasing levels of alcohol consumption were significantly associated with more episodes of depression (OR 1.35, P < .001) and mania (OR 1.30, P < .004) per illness year, less impairment in functioning during the worst episode of mania (OR 1.02, P < .001), fewer psychiatric admissions (OR 0.51, P < .001), comorbid panic disorder (OR 2.16, P < .001) and eating disorder (OR 2.37, P < .001).

Conclusions: Our results highlight the clinical importance of obtaining detailed information on levels of alcohol consumption among patients with BD. Increased levels of alcohol use, not necessarily reaching criteria for AUD, may be helpful in predicting BD illness course, in particular eating disorders comorbidity in women.
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http://dx.doi.org/10.1111/bdi.12905DOI Listing
November 2020

Symptom profile of postpartum and non-postpartum manic episodes in bipolar I disorder: a within-subjects study.

Psychiatry Res 2020 02 2;284:112748. Epub 2020 Jan 2.

National Centre for Mental Health, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, 3.06, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK. Electronic address:

The relationship of postpartum mania to episodes of mania occurring outside the perinatal period among women with bipolar disorder remains controversial. Previous studies have used between-subjects designs to compare the clinical presentations of these episodes meaning the differences, in part, may reflect between-group differences. To overcome this we have undertaken within-subject comparisons of the symptom profile of postpartum and non-postpartum manic episodes in 50 women with DSM-IV bipolar I disorder. For each woman detailed symptom information on a postpartum episode of mania and a comparison non-postpartum manic episode was collected. The occurrence of manic, psychotic and depressive symptoms in these episodes were compared. Postpartum manic episodes had a significantly higher incidence of perplexity and excessive self-reproach. Classic manic symptoms, specifically pressured speech and increased sociability, were significantly less frequent in postpartum manic episodes. Overall there were significantly fewer manic symptoms and significantly more depressive symptoms in the postpartum episodes than in the non-postpartum episodes. The mixed presentation of postpartum manic episodes suggests childbirth may act as a pathoplastic trigger in women with bipolar disorder. The differences in symptom profiles suggests further research is warranted into whether differences in treatment response exist among women experiencing postpartum and non-postpartum manic episodes.
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http://dx.doi.org/10.1016/j.psychres.2020.112748DOI Listing
February 2020

International Consortium on the Genetics of Electroconvulsive Therapy and Severe Depressive Disorders (Gen-ECT-ic).

Eur Arch Psychiatry Clin Neurosci 2020 Oct 4;270(7):921-932. Epub 2019 Dec 4.

Department of Mental Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA.

Recent genome-wide association studies have demonstrated that the genetic burden associated with depression correlates with depression severity. Therefore, conducting genetic studies of patients at the most severe end of the depressive disorder spectrum, those with treatment-resistant depression and who are prescribed electroconvulsive therapy (ECT), could lead to a better understanding of the genetic underpinnings of depression. Despite ECT being one of the most effective forms of treatment for severe depressive disorders, it is usually placed at the end of treatment algorithms of current guidelines. This is perhaps because ECT has controlled risk and logistical demands including use of general anaesthesia and muscle relaxants and side-effects such as short-term memory impairment. Better understanding of the genetics and biology of ECT response and of cognitive side-effects could lead to more personalized treatment decisions. To enhance the understanding of the genomics of severe depression and ECT response, researchers and ECT providers from around the world and from various depression or ECT networks, but not limited to, such as the Psychiatric Genomics Consortium, the Clinical Alliance and Research in ECT, and the National Network of Depression Centers have formed the Genetics of ECT International Consortium (Gen-ECT-ic). Gen-ECT-ic will organize the largest clinical and genetic collection to date to study the genomics of severe depressive disorders and response to ECT, aiming for 30,000 patients worldwide using a GWAS approach. At this stage it will be the largest genomic study on treatment response in depression. Retrospective data abstraction and prospective data collection will be facilitated by a uniform data collection approach that is flexible and will incorporate data from many clinical practices. Gen-ECT-ic invites all ECT providers and researchers to join its efforts.
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http://dx.doi.org/10.1007/s00406-019-01087-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385979PMC
October 2020

Comparison of Genetic Liability for Sleep Traits Among Individuals With Bipolar Disorder I or II and Control Participants.

JAMA Psychiatry 2020 03;77(3):303-310

Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom.

Importance: Insomnia, hypersomnia, and an evening chronotype are common in individuals with bipolar disorder (BD), but whether this reflects shared genetic liability is unclear. Stratifying by BD subtypes could elucidate this association and inform sleep and BD research.

Objective: To assess whether polygenic risk scores (PRSs) for sleep traits are associated with BD subtypes I and II.

Design, Setting, And Participants: This case-control study was conducted in the United Kingdom and Sweden with participants with BD and control participants. Multinomial regression was used to assess whether PRSs for insomnia, daytime sleepiness, sleep duration, and chronotype are associated with BD subtypes compared with control participants. Affected individuals were recruited from the Bipolar Disorder Research Network. Control participants were recruited from the 1958 British Birth Cohort and the UK Blood Service. Analyses were repeated in an independent Swedish sample from August 2018 to July 2019. All participants were of European ancestry.

Exposures: Standardized PRSs derived using alleles from genome-wide association studies of insomnia, sleep duration, daytime sleepiness, and chronotype. These were adjusted for the first 10 population principal components, genotyping platforms, and sex.

Main Outcomes And Measures: Association of PRSs with BD subtypes, determined by semistructured psychiatric interview and case notes.

Results: The main analysis included 4672 participants with BD (3132 female participants [67.0%]; 3404 with BD-I [72.9%]) and 5714 control participants (2812 female participants [49.2%]). Insomnia PRS was associated with increased risk of BD-II (relative risk [RR], 1.14 [95% CI, 1.07-1.21]; P = 8.26 × 10-5) but not BD-I (RR, 0.98 [95% CI, 0.94-1.03]; P = .409) relative to control participants. Sleep-duration PRS was associated with BD-I (RR, 1.10 [95% CI, 1.06-1.15]; P = 1.13 × 10-5) but not BD-II (RR, 0.99 [95% CI, 0.93-1.06]; P = .818). Associations between (1) insomnia PRS and BD-II and (2) sleep-duration PRS and BD-I were replicated in the Swedish sample of 4366 individuals with BD (2697 female participants [61.8%]; 2627 with BD-I [60.2%]) and 6091 control participants (3767 female participants [61.8%]). Chronotype and daytime-sleepiness PRS were not associated with BD subtypes.

Conclusions And Relevance: Per this analysis, BD subtypes differ in genetic liability to insomnia and hypersomnia, providing further evidence that the distinction between BD-I and BD-II has genetic validity. This distinction will be crucial in selecting participants for future research on the role of sleep disturbance in BD.
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http://dx.doi.org/10.1001/jamapsychiatry.2019.4079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902167PMC
March 2020

Adverse childhood experiences and postpartum depression in bipolar disorder.

J Affect Disord 2020 02 11;263:661-666. Epub 2019 Nov 11.

Institute of Psychological Medicine & Clinical Neurosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.

Background: Women are particularly vulnerable to recurrence of bipolar disorder (BD) following childbirth. Risk of postpartum psychosis (PP) is especially high, but postpartum depression (PPD) is also common. Adverse childhood experiences (ACEs) have not been associated with PP, but have been associated with PPD in non-bipolar samples. The relationship between ACEs and PPD within BD remains to be investigated. Here, we examined this association in a large, well-defined sample of women with BD.

Methods: Participants were 575 parous women with DSM-IV BD. Lifetime psychopathology, including perinatal, was assessed via semi-structured interview and case-notes. ACEs, assessed via self-report and case-notes, were compared between women with lifetime PPD (n = 368) and those without a lifetime history of perinatal mood episodes (n = 207).

Results: In univariate analysis exposure to 3 or more ACEs, and to childhood abuse specifically, was significantly associated with PPD (p = 0.026 and 0.041 respectively), but this did not remain significant after adjusting for lifetime number of episodes of depression and parity. Post-hoc analysis revealed more frequent episodes of depression to be associated with both a history of 3 or more ACEs and of childhood abuse.

Limitations: Limited range of ACEs assessed and potential recall bias.

Conclusions: Increased frequency of ACEs and particularly childhood abuse was associated with more frequent lifetime episodes of depression, but not specifically episodes with postpartum onset. Understanding factors that mediate the pathway between ACEs and PPD in BD has implications for risk prediction of PPD.
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http://dx.doi.org/10.1016/j.jad.2019.11.042DOI Listing
February 2020

Explaining why childhood abuse is a risk factor for poorer clinical course in bipolar disorder: a path analysis of 923 people with bipolar I disorder.

Psychol Med 2020 10 18;50(14):2346-2354. Epub 2019 Sep 18.

Psychological Medicine, University of Worcester, Worcester, UK.

Background: Childhood abuse is a risk factor for poorer illness course in bipolar disorder, but the reasons why are unclear. Trait-like features such as affective instability and impulsivity could be part of the explanation. We aimed to examine whether childhood abuse was associated with clinical features of bipolar disorder, and whether associations were mediated by affective instability or impulsivity.

Methods: We analysed data from 923 people with bipolar I disorder recruited by the Bipolar Disorder Research Network. Adjusted associations between childhood abuse, affective instability and impulsivity and eight clinical variables were analysed. A path analysis examined the direct and indirect links between childhood abuse and clinical features with affective instability and impulsivity as mediators.

Results: Affective instability significantly mediated the association between childhood abuse and earlier age of onset [effect estimate (θ)/standard error (SE): 2.49], number of depressive (θ/SE: 2.08) and manic episodes/illness year (θ/SE: 1.32), anxiety disorders (θ/SE: 1.98) and rapid cycling (θ/SE: 2.25). Impulsivity significantly mediated the association between childhood abuse and manic episodes/illness year (θ/SE: 1.79), anxiety disorders (θ/SE: 1.59), rapid cycling (θ/SE: 1.809), suicidal behaviour (θ/SE: 2.12) and substance misuse (θ/SE: 3.09). Measures of path analysis fit indicated an excellent fit to the data.

Conclusions: Affective instability and impulsivity are likely part of the mechanism of why childhood abuse increases risk of poorer clinical course in bipolar disorder, with each showing some selectivity in pathways. They are potential novel targets for intervention to improve outcome in bipolar disorder.
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http://dx.doi.org/10.1017/S0033291719002411DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7610181PMC
October 2020

Polygenic risk for circulating reproductive hormone levels and their influence on hippocampal volume and depression susceptibility.

Psychoneuroendocrinology 2019 08 20;106:284-292. Epub 2019 Apr 20.

Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK. Electronic address:

Altered reproductive hormone levels have been associated with the pathophysiology of depressive disorders and this risk may be imparted by their modulatory effect upon hippocampal structure and function. Currently it is unclear whether altered levels of reproductive hormones are causally associated with hippocampal volume reductions and the risk of depressive disorders. Here, we utilize genome-wide association study (GWAS) summary statistics from a GWAS focusing on reproductive hormones, consisting of 2913 individuals. Using this data, we generated polygenic risk scores (PRS) for estradiol, progesterone, prolactin and testosterone in the European RADIANT cohort consisting of 176 postpartum depression (PPD) cases (100% female, mean age: 41.6 years old), 2772 major depressive disorder (MDD) cases (68.6% female, mean age: 46.9 years old) and 1588 control participants (62.5% female, mean age: 42.4 years old), for which there was also a neuroimaging subset of 111 individuals (60.4% female, mean age: 50.0 years old). Only the best-fit PRS for estradiol showed a significant negative association with hippocampal volume, as well as many of its individual subfields; including the molecular layer and granule cell layer of the dentate gyrus, subiculum, CA1, CA2/3 and CA4 regions. Interestingly, several of these subfields are implicated in adult hippocampal neurogenesis. When we tested the same estradiol PRS for association with case-control status for PPD or MDD there was no significant relationship observed. Here, we provide evidence that genetic risk for higher plasma estradiol is negatively associated with hippocampal volume, but this does not translate into an increased risk of MDD or PPD. This work suggests that the relationship between reproductive hormones, the hippocampus, and depression is complex, and that there may not be a clear-cut pathway for etiology or risk moderation.
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http://dx.doi.org/10.1016/j.psyneuen.2019.04.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6597945PMC
August 2019

Agitated depression in bipolar disorder.

Bipolar Disord 2019 09 6;21(6):547-555. Epub 2019 May 6.

Psychological Medicine, University of Worcester, UK.

Objectives: It has been suggested that agitated depression (AD) is a common, severe feature in bipolar disorder. We aimed to estimate the prevalence of AD and investigate whether presence of AD was associated with episodic and lifetime clinical features in a large well-characterized bipolar disorder sample.

Method: The prevalence of agitation, based on semi-structured interview and medical case-notes, in the most severe depressive episode was estimated in 2925 individuals with DSM-IV bipolar disorder recruited into the UK Bipolar Disorder Research Network. Predictors of agitation were ascertained using symptoms within the same episode and lifetime clinical features using multivariate models.

Results: 32.3% (n = 946) experienced agitation during the worst depressive episode. Within the same episode, significant predictors of presence of agitation were: insomnia (OR 2.119, P < 0.001), poor concentration (OR 1.966, P = 0.027), decreased libido (OR 1.960, P < 0.001), suicidal ideation (OR 1.861, P < 0.001), slowed activity (OR 1.504, P = 0.001), and poor appetite (OR 1.297, P = 0.029). Over the lifetime illness course, co-morbid panic disorder (OR 2.000, P < 0.001), suicide attempt (OR 1.399, P = 0.007), and dysphoric mania (OR 1.354, P = 0.017) were significantly associated with AD.

Conclusions: Agitation accompanied bipolar depression in at least one-third of cases in our sample and was associated with concurrent somatic depressive symptoms, which are also common features of mixed manic states. Furthermore, AD in our sample was associated with lifetime experience of mixed mania, in addition to severe lifetime illness course including comorbid panic disorder and suicidal behavior. Our results have implications for the diagnosis and treatment of agitated features in bipolar depression.
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http://dx.doi.org/10.1111/bdi.12778DOI Listing
September 2019

Genome-wide Burden of Rare Short Deletions Is Enriched in Major Depressive Disorder in Four Cohorts.

Biol Psychiatry 2019 06 13;85(12):1065-1073. Epub 2019 Mar 13.

Department of Biological Psychology, Amsterdam Public Health Research Institute, Amsterdam, the Netherlands.

Background: Major depressive disorder (MDD) is moderately heritable, with a high prevalence and a presumed high heterogeneity. Copy number variants (CNVs) could contribute to the heritable component of risk, but the two previous genome-wide association studies of rare CNVs did not report significant findings.

Methods: In this meta-analysis of four cohorts (5780 patients and 6626 control subjects), we analyzed the association of MDD to 1) genome-wide burden of rare deletions and duplications, partitioned by length (<100 kb or >100 kb) and other characteristics, and 2) individual rare exonic CNVs and CNV regions.

Results: Patients with MDD carried significantly more short deletions than control subjects (p = .0059) but not long deletions or short or long duplications. The confidence interval for long deletions overlapped with that for short deletions, but long deletions were 70% less frequent genome-wide, reducing the power to detect increased burden. The increased burden of short deletions was primarily in intergenic regions. Short deletions in cases were also modestly enriched for high-confidence enhancer regions. No individual CNV achieved thresholds for suggestive or significant association after genome-wide correction. p values < .01 were observed for 15q11.2 duplications (TUBGCP5, CYFIP1, NIPA1, and NIPA2), deletions in or near PRKN or MSR1, and exonic duplications of ATG5.

Conclusions: The increased burden of short deletions in patients with MDD suggests that rare CNVs increase the risk of MDD by disrupting regulatory regions. Results for longer deletions were less clear, but no large effects were observed for long multigenic CNVs (as seen in schizophrenia and autism). Further studies with larger sample sizes are warranted.
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http://dx.doi.org/10.1016/j.biopsych.2019.02.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6750266PMC
June 2019

Contribution of Rare Copy Number Variants to Bipolar Disorder Risk Is Limited to Schizoaffective Cases.

Biol Psychiatry 2019 07 20;86(2):110-119. Epub 2018 Dec 20.

Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.

Background: Genetic risk for bipolar disorder (BD) is conferred through many common alleles, while a role for rare copy number variants (CNVs) is less clear. Subtypes of BD including schizoaffective disorder bipolar type (SAB), bipolar I disorder (BD I), and bipolar II disorder (BD II) differ according to the prominence and timing of psychosis, mania, and depression. The genetic factors contributing to the combination of symptoms among these subtypes are poorly understood.

Methods: Rare large CNVs were analyzed in 6353 BD cases (3833 BD I [2676 with psychosis, 850 without psychosis, and 307 with unknown psychosis history], 1436 BD II, 579 SAB, and 505 BD not otherwise specified) and 8656 controls. CNV burden and a polygenic risk score (PRS) for schizophrenia were used to evaluate the relative contributions of rare and common variants to risk of BD, BD subtypes, and psychosis.

Results: CNV burden did not differ between BD and controls when treated as a single diagnostic entity. However, burden in SAB was increased relative to controls (p = .001), BD I (p = .0003), and BD II (p = .0007). Burden and schizophrenia PRSs were increased in SAB compared with BD I with psychosis (CNV p = .0007, PRS p = .004), and BD I without psychosis (CNV p = .0004, PRS p = 3.9 × 10). Within BD I, psychosis was associated with increased schizophrenia PRSs (p = .005) but not CNV burden.

Conclusions: CNV burden in BD is limited to SAB. Rare and common genetic variants may contribute differently to risk for psychosis and perhaps other classes of psychiatric symptoms.
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http://dx.doi.org/10.1016/j.biopsych.2018.12.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6586545PMC
July 2019

Large-scale roll out of electronic longitudinal mood-monitoring for research in affective disorders: Report from the UK bipolar disorder research network.

J Affect Disord 2019 03 25;246:789-793. Epub 2018 Dec 25.

Psychological Medicine, University of Worcester, Henwick Grove, Worcester, WR2 6AJ, UK. Electronic address:

Background: Electronic longitudinal mood monitoring has been shown to be acceptable to patients with affective disorders within clinical settings, but its use in large-scale research has not yet been established.

Methods: Using both postal and email invitations, we invited 4080 past research participants with affective disorders who were recruited into the Bipolar Disorder Research Network (BDRN) over a 10 year period to participate in online weekly mood monitoring. In addition, since January 2015 we have invited all newly recruited BDRN research participants to participate in mood monitoring at the point they were recruited into BDRN.

Results: Online mood monitoring uptake among past participants was 20%, and among new participants to date was 46% with participants recruited over the last year most likely to register (61%). More than 90% mood monitoring participants engaged for at least one month, with mean engagement period greater than one year (58 weeks) and maximum engagement for longer than three years (165 weeks). There were no significant differences in the proportion of past and new BDRN participants providing data for at least 4 weeks (91%, 92% respectively), 3 months (78%, 82%), 6 months (65%, 54%) or one year (51%, 44%).

Limitations: Our experiences with recruiting participants for electronic prospective mood monitoring may not necessarily generalise fully to research situations that are very different from those we describe.

Conclusions: Large-scale electronic longitudinal mood monitoring in affective disorders for research purposes is feasible with uptake highest among newly recruited participants.
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http://dx.doi.org/10.1016/j.jad.2018.12.099DOI Listing
March 2019

Genotype-phenotype correlations in Darier disease: A focus on the neuropsychiatric phenotype.

Am J Med Genet B Neuropsychiatr Genet 2018 12 22;177(8):717-726. Epub 2018 Oct 22.

Department of Psychological Medicine, University of Worcester, Worcester, United Kingdom.

Darier disease (DD) is an autosomal dominant skin disorder caused by mutations in ATP2A2 encoding the sarco/endoplasmic reticulum Ca ATPase Isoform 2 (SERCA2). Evidence of a population-level association between DD and psychiatric disorders suggests that mutations in ATP2A2 may have pleiotropic effects on the brain as well as skin. Evidence of genotype-phenotype relationships between ATP2A2 mutations and neuropsychiatric phenotypes would further support this suggestion. We investigated genotype-phenotype correlations between lifetime neuropsychiatric features and ATP2A2 mutation type (dichotomized into likely gene disrupting [LGD] or protein altering) in 75 unrelated individuals with DD. We also looked for evidence of clustering of mutations within SERCA2 according to neuropsychiatric features. Combining our data with the existing literature, the rate of LGD mutations was found to be significantly higher among DD cases/families with bipolar disorder, schizophrenia, or affective psychosis (p = .011). We also found a significant relationship between mutations located in the S4-M4 region of the protein and the presence of a severe neuropsychiatric phenotype (p = .032). Our findings add support to the hypothesis that Darier-causing mutations in ATP2A2 confer susceptibility to neuropsychiatric dysfunction, in particular severe psychiatric illness. This, together with evidence from research on common polymorphisms confirms ATP2A2 as a gene at which variation influences susceptibility to major psychiatric illness.
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http://dx.doi.org/10.1002/ajmg.b.32679DOI Listing
December 2018

Stratification of the risk of bipolar disorder recurrences in pregnancy and postpartum.

Br J Psychiatry 2018 09;213(3):542-547

Institute of Psychological Medicine and Clinical Neurosciences,Cardiff University,UKandDepartment of Psychological Medicine,University of Worcester,UK.

Background: Pregnancy and childbirth are a period of high risk for women with bipolar disorder and involve difficult decisions particularly about continuing or stopping medications.AimsTo explore what clinical predictors may help to individualise the risk of perinatal recurrence in women with bipolar disorder.

Method: Information was gathered retrospectively by semi-structured interview, questionnaires and case-note review from 887 women with bipolar disorder who have had children. Clinical predictors were selected using backwards stepwise logistic regression, conditional permutation random forests and reinforcement learning trees.

Results: Previous perinatal history of affective psychosis or depression was the most significant predictor of a perinatal recurrence (odds ratio (OR) = 8.5, 95% CI 5.04-14.82 and OR = 3.6, 95% CI 2.55-5.07 respectively) but even parous women with bipolar disorder without a previous perinatal mood episode were at risk following a subsequent pregnancy, with 7% developing postpartum psychosis.

Conclusions: Previous perinatal history of affective psychosis or depression is the most important predictor of perinatal recurrence in women with bipolar disorder and can be used to individualise risk assessments.Declaration of interestNone.
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http://dx.doi.org/10.1192/bjp.2018.92DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6429257PMC
September 2018

Analysis of shared heritability in common disorders of the brain.

Science 2018 06;360(6395)

Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.

Disorders of the brain can exhibit considerable epidemiological comorbidity and often share symptoms, provoking debate about their etiologic overlap. We quantified the genetic sharing of 25 brain disorders from genome-wide association studies of 265,218 patients and 784,643 control participants and assessed their relationship to 17 phenotypes from 1,191,588 individuals. Psychiatric disorders share common variant risk, whereas neurological disorders appear more distinct from one another and from the psychiatric disorders. We also identified significant sharing between disorders and a number of brain phenotypes, including cognitive measures. Further, we conducted simulations to explore how statistical power, diagnostic misclassification, and phenotypic heterogeneity affect genetic correlations. These results highlight the importance of common genetic variation as a risk factor for brain disorders and the value of heritability-based methods in understanding their etiology.
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http://dx.doi.org/10.1126/science.aap8757DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097237PMC
June 2018

Analysis of shared heritability in common disorders of the brain.

Science 2018 06;360(6395)

Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.

Disorders of the brain can exhibit considerable epidemiological comorbidity and often share symptoms, provoking debate about their etiologic overlap. We quantified the genetic sharing of 25 brain disorders from genome-wide association studies of 265,218 patients and 784,643 control participants and assessed their relationship to 17 phenotypes from 1,191,588 individuals. Psychiatric disorders share common variant risk, whereas neurological disorders appear more distinct from one another and from the psychiatric disorders. We also identified significant sharing between disorders and a number of brain phenotypes, including cognitive measures. Further, we conducted simulations to explore how statistical power, diagnostic misclassification, and phenotypic heterogeneity affect genetic correlations. These results highlight the importance of common genetic variation as a risk factor for brain disorders and the value of heritability-based methods in understanding their etiology.
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http://dx.doi.org/10.1126/science.aap8757DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097237PMC
June 2018

A data-driven investigation of relationships between bipolar psychotic symptoms and schizophrenia genome-wide significant genetic loci.

Am J Med Genet B Neuropsychiatr Genet 2018 06 19;177(4):468-475. Epub 2018 Apr 19.

MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University Institute of Psychological Medicine and Clinical Neurosciences, Cardiff, United Kingdom.

The etiologies of bipolar disorder (BD) and schizophrenia include a large number of common risk alleles, many of which are shared across the disorders. BD is clinically heterogeneous and it has been postulated that the pattern of symptoms is in part determined by the particular risk alleles carried, and in particular, that risk alleles also confer liability to schizophrenia influence psychotic symptoms in those with BD. To investigate links between psychotic symptoms in BD and schizophrenia risk alleles we employed a data-driven approach in a genotyped and deeply phenotyped sample of subjects with BD. We used sparse canonical correlation analysis (sCCA) (Witten, Tibshirani, & Hastie, ) to analyze 30 psychotic symptoms, assessed with the OPerational CRITeria checklist, and 82 independent genome-wide significant single nucleotide polymorphisms (SNPs) identified by the Schizophrenia Working group of the Psychiatric Genomics Consortium for which we had data in our BD sample (3,903 subjects). As a secondary analysis, we applied sCCA to larger groups of SNPs, and also to groups of symptoms defined according to a published factor analyses of schizophrenia. sCCA analysis based on individual psychotic symptoms revealed a significant association (p = .033), with the largest weights attributed to a variant on chromosome 3 (rs11411529), chr3:180594593, build 37) and delusions of influence, bizarre behavior and grandiose delusions. sCCA analysis using the same set of SNPs supported association with the same SNP and the group of symptoms defined "factor 3" (p = .012). A significant association was also observed to the "factor 3" phenotype group when we included a greater number of SNPs that were less stringently associated with schizophrenia; although other SNPs contributed to the significant multivariate association result, the greatest weight remained assigned to rs11411529. Our results suggest that the canonical correlation is a useful tool to explore phenotype-genotype relationships. To the best of our knowledge, this is the first study to apply this approach to complex, polygenic psychiatric traits. The sparse canonical correlation approach offers the potential to include a larger number of fine-grained systematic descriptors, and to include genetic markers associated with other disorders that are genetically correlated with BD.
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http://dx.doi.org/10.1002/ajmg.b.32635DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6001555PMC
June 2018

Pamela Sklar 1959-2017.

Nat Neurosci 2018 Feb;21(2):151

MRC Centre For Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.

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http://dx.doi.org/10.1038/s41593-017-0067-zDOI Listing
February 2018

Mania triggered by sleep loss and risk of postpartum psychosis in women with bipolar disorder.

J Affect Disord 2018 01 18;225:624-629. Epub 2017 Aug 18.

Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. Electronic address:

Background: Women with bipolar disorder are at high risk of affective psychoses following childbirth (i.e. "postpartum psychosis", PP) and there is a need to identify which factors underlie this increased risk. Vulnerability to mood dysregulation following sleep loss may influence risk of PP, as childbirth is typified by sleep disruption. We investigated whether a history of mood episodes triggered by sleep loss was associated with PP in women with bipolar disorder (BD).

Methods: Participants were 870 parous women with BD recruited to the Bipolar Disorder Research Network. Lifetime diagnoses of BD and perinatal episodes were identified via interview and case notes. Information on whether mood episodes had been triggered by sleep loss was derived at interview. Rates of PP were compared between women who did and did not report mood episodes following sleep loss.

Results: Women who reported sleep loss triggering episodes of mania were twice as likely to have experienced an episode of PP (OR = 2.09, 95% CI = 1.47-2.97, p < 0.001) compared to women who did not report this. There was no significant association between depression triggered by sleep loss and PP (p = 0.526).

Limitations: Data were cross-sectional therefore may be subject to recall bias. We also did not have objective data on sleep disruption that had occurred during the postpartum period or prior to mood episodes.

Conclusions: In clinical practice, a history of mania following sleep loss could be a marker of increased vulnerability to PP, and should be discussed with BD women who are pregnant or planning to conceive.
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http://dx.doi.org/10.1016/j.jad.2017.08.054DOI Listing
January 2018

Genome-wide significant locus for Research Diagnostic Criteria Schizoaffective Disorder Bipolar type.

Am J Med Genet B Neuropsychiatr Genet 2017 Dec 29;174(8):767-771. Epub 2017 Aug 29.

MRC Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.

Studies have suggested that Research Diagnostic Criteria for Schizoaffective Disorder Bipolar type (RDC-SABP) might identify a more genetically homogenous subgroup of bipolar disorder. Aiming to identify loci associated with RDC-SABP, we have performed a replication study using independent RDC-SABP cases (n = 144) and controls (n = 6,559), focusing on the 10 loci that reached a p-value <10 for RDC-SABP in the Wellcome Trust Case Control Consortium (WTCCC) bipolar disorder sample. Combining the WTCCC and replication datasets by meta-analysis (combined RDC-SABP, n = 423, controls, n = 9,494), we observed genome-wide significant association at one SNP, rs2352974, located within the intron of the gene TRAIP on chromosome 3p21.31 (p-value, 4.37 × 10 ). This locus did not reach genome-wide significance in bipolar disorder or schizophrenia large Psychiatric Genomic Consortium datasets, suggesting that it may represent a relatively specific genetic risk for the bipolar subtype of schizoaffective disorder.
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http://dx.doi.org/10.1002/ajmg.b.32572DOI Listing
December 2017

Changes to the Diagnostic Criteria for Bipolar Disorder in DSM-5 Make Little Difference to Lifetime Diagnosis: Findings From the U.K. Bipolar Disorder Research Network (BDRN) Study.

Am J Psychiatry 2017 08;174(8):803

From the Department of Psychological Medicine, University of Worcester, Worcester, U.K.; and the Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University School of Medicine, Cardiff, U.K.

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http://dx.doi.org/10.1176/appi.ajp.2017.17010109DOI Listing
August 2017

Sleep loss as a trigger of mood episodes in bipolar disorder: individual differences based on diagnostic subtype and gender.

Br J Psychiatry 2017 Sep 6;211(3):169-174. Epub 2017 Jul 6.

Katie Swaden Lewis, BSc, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatry Genetics and Genomics, Cardiff University, Cardiff; Katherine Gordon-Smith, PhD, Institute of Health & Society, University of Worcester, Worcester; Liz Forty, PhD, National Centre for Mental Health, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff; Arianna Di Florio, PhD, MD, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff; Nick Craddock, PhD, FRCPsych, National Centre for Mental Health, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff; Lisa Jones, PhD, Institute of Health & Society, University of Worcester, Worcester; Ian Jones, PhD, MRCPsych, National Centre for Mental Health, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK

Sleep loss may trigger mood episodes in people with bipolar disorder but individual differences could influence vulnerability to this trigger.To determine whether bipolar subtype (bipolar disorder type I (BP-I) or II (BD-II)) and gender were associated with vulnerability to the sleep loss trigger.During a semi-structured interview, 3140 individuals (68% women) with bipolar disorder (66% BD-I) reported whether sleep loss had triggered episodes of high or low mood. DSM-IV diagnosis of bipolar subtype was derived from case notes and interview data.Sleep loss triggering episodes of high mood was associated with female gender (odds ratio (OR) = 1.43, 95% CI 1.17-1.75, < 0.001) and BD-I subtype (OR = 2.81, 95% CI 2.26-3.50, < 0.001). Analyses on sleep loss triggering low mood were not significant following adjustment for confounders.Gender and bipolar subtype may increase vulnerability to high mood following sleep deprivation. This should be considered in situations where patients encounter sleep disruption, such as shift work and international travel.
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http://dx.doi.org/10.1192/bjp.bp.117.202259DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579327PMC
September 2017

Interaction between the gene, body mass index and depression: meta-analysis of 13701 individuals.

Br J Psychiatry 2017 08 22;211(2):70-76. Epub 2017 Jun 22.

Margarita Rivera, PhD, Department of Biochemistry and Molecular Biology II and Institute of Neurosciences, Center for Biomedical Research, University of Granada, Granada, Spain, and MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, Kinǵs College London, UK; Adam E. Locke, PhD, Department of Biostatistics and Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan, USA; Tanguy Corre, PhD, Department of Medical Genetics, University of Lausanne, Lausanne, and Swiss Institute of Bioinformatics, Lausanne, Switzerland; Darina Czamara, PhD, Christiane Wolf, PhD, Max Planck Institute of Psychiatry, Munich, Germany; Ana Ching-Lopez, Department of Psychiatry, School of Medicine, University of Granada, and Institute of Neurosciences Federico Olóriz, Centra de Investigación Biomédica, University of Granada, Spain; Yuri Milaneschi, PhD, Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center/GGZ in Geest, Amsterdam, The Netherlands; Stefan Kloiber, MD, Max Planck Institute of Psychiatry, Munich, Germany; Sara Cohen-Woods, PhD, School of Psychology, Flinders University, Adelaide, South Australia, Australia; James Rucker, MD, PhD, MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK; Katherine J. Aitchison, MD, PhD, Department of Psychiatry, University of Alberta, Alberta, Canada; Sven Bergmann, PhD, Department of Medical Genetics, University of Lausanne, Lausanne, and Swiss Institute of Bioinformatics, Lausanne, Switzerland; Dorret I. Boomsma, PhD, Department of Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands; Nick Craddock, MB, PhD, FMedSci, Department of Psychological Medicine and Neurology, Cardiff University School of Medicine, Henry Wellcome Building, Cardiff, UK; Michael Gill, MD, Department of Psychiatry, Trinity Centre for Health Sciences, Dublin 8, Ireland; Florian Holsboer, MD, PhD, Max Planck Institute of Psychiatry, Munich, Germany; Jouke-Jan Hottenga, PhD, Department of Psychiatry, University of Alberta, Alberta, Canada; Ania Korszun, PhD, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK; Zoltan Kutalik, PhD, Department of Medical Genetics, University of Lausanne, Lausanne, and Swiss Institute of Bioinformatics, Lausanne, Switzerland; Susanne Lucae, MD, PhD, Max Planck Institute of Psychiatry, Munich, Germany; Wolfgang Maier, MD, Department of Psychiatry, University of Bonn, Bonn, Germany; Ole Mors, MD, PhD, Research Department P, Aarhus University Hospital, Risskov, Denmark; Bertram Müller-Myhsok MD, Max Planck Institute of Psychiatry, Munich, Germany; Michael J. Owen, MB, PhD, FMedSci, MRC Centre for Neuropsychiatry Genetics and Genomics, Department of Psychological Medicine and Neurology, School of Medicine, Cardiff University, Cardiff, UK; Brenda W. J. H. Penninx, PhD, Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center/GGZ in Geest, Amsterdam, The Netherlands; Martin Preisig, MD, Department of Psychiatry, Lausanne University Hospital, 1008 Prilly-Lausanne, Switzerland; John Rice, PhD, Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA; Marcella Rietschel, MD, Central Institute of Mental Health, Mannheim, Germany; Federica Tozzi, MD, Genetics Division, Drug Discovery, GlaxoSmithKline Research and Development, Verona, Italy; Rudolf Uher, MD, PhD, MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK, and Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada; Peter Vollenweider, MD, PhD, Gerard Waeber, MD, PhD, Division of Internal Medicine, CHUV, Lausanne, Switzerland; Gonneke Willemsen, PhD, Department of Psychiatry, University of Alberta, Alberta, Canada; Ian W. Craig, PhD, Anne E. Farmer, MD, MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK; Cathryn M. Lewis, PhD, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, and Department of Medical and Molecular Genetics, School of Medicine, King's College London, UK; Gerome Breen, PhD, Peter McGuffin, MB, PhD, FMedSci, MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK.

Depression and obesity are highly prevalent, and major impacts on public health frequently co-occur. Recently, we reported that having depression moderates the effect of the gene, suggesting its implication in the association between depression and obesity.To confirm these findings by investigating the polymorphism rs9939609 in new cohorts, and subsequently in a meta-analysis.The sample consists of 6902 individuals with depression and 6799 controls from three replication cohorts and two original discovery cohorts. Linear regression models were performed to test for association between rs9939609 and body mass index (BMI), and for the interaction between rs9939609 and depression status for an effect on BMI. Fixed and random effects meta-analyses were performed using METASOFT.In the replication cohorts, we observed a significant interaction between , BMI and depression with fixed effects meta-analysis (β = 0.12, = 2.7 × 10) and with the Han/Eskin random effects method ( = 1.4 × 10) but not with traditional random effects (β = 0.1, = 0.35). When combined with the discovery cohorts, random effects meta-analysis also supports the interaction (β = 0.12, = 0.027) being highly significant based on the Han/Eskin model ( = 6.9 × 10). On average, carriers of the risk allele who have depression have a 2.2% higher BMI for each risk allele, over and above the main effect of This meta-analysis provides additional support for a significant interaction between , depression and BMI, indicating that depression increases the effect of on BMI. The findings provide a useful starting point in understanding the biological mechanism involved in the association between obesity and depression.
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http://dx.doi.org/10.1192/bjp.bp.116.183475DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537566PMC
August 2017

Contribution of copy number variants to schizophrenia from a genome-wide study of 41,321 subjects.

Nat Genet 2017 01 21;49(1):27-35. Epub 2016 Nov 21.

Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.

Copy number variants (CNVs) have been strongly implicated in the genetic etiology of schizophrenia (SCZ). However, genome-wide investigation of the contribution of CNV to risk has been hampered by limited sample sizes. We sought to address this obstacle by applying a centralized analysis pipeline to a SCZ cohort of 21,094 cases and 20,227 controls. A global enrichment of CNV burden was observed in cases (odds ratio (OR) = 1.11, P = 5.7 × 10), which persisted after excluding loci implicated in previous studies (OR = 1.07, P = 1.7 × 10). CNV burden was enriched for genes associated with synaptic function (OR = 1.68, P = 2.8 × 10) and neurobehavioral phenotypes in mouse (OR = 1.18, P = 7.3 × 10). Genome-wide significant evidence was obtained for eight loci, including 1q21.1, 2p16.3 (NRXN1), 3q29, 7q11.2, 15q13.3, distal 16p11.2, proximal 16p11.2 and 22q11.2. Suggestive support was found for eight additional candidate susceptibility and protective loci, which consisted predominantly of CNVs mediated by nonallelic homologous recombination.
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http://dx.doi.org/10.1038/ng.3725DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5737772PMC
January 2017

Autistic and schizotypal traits and global functioning in bipolar I disorder.

J Affect Disord 2017 Jan 3;207:268-275. Epub 2016 Oct 3.

Department of Psychological Medicine, University of Worcester, Worcester, United Kingdom. Electronic address:

Objective: To determine the expression of autistic and positive schizotypal traits in a large sample of adults with bipolar I disorder (BD I), and the effect of co-occurring autistic and positive schizotypal traits on global functioning in BD I.

Method: Autistic and positive schizotypal traits were self-assessed in 797 individuals with BD-I recruited by the Bipolar Disorder Research Network. Differences in global functioning (rated using the Global Assessment Scale) during lifetime worst depressive and manic episodes (GASD and GASM respectively) were calculated in groups with high/low autistic and positive schizotypal traits. Regression analyses assessed the interactive effect of autistic and positive schizotypal traits on global functioning.

Results: 47.2% (CI=43.7-50.7%) showed clinically significant levels of autistic traits, and 23.22% (95% CI=20.29-26.14) showed clinically significant levels of positive schizotypal traits. In the worst episode of mania, the high autistic, high positive schizotypal group had better global functioning compared to the other groups. Individual differences analyses showed that high levels of both traits were associated with better global functioning in both mood states.

Limitations: Autistic and schizotypal traits were assessed using self-rated questionnaires.

Conclusions: Expression of autistic and schizotypal traits in adults with BD I is prevalent, and may be important to predict illness aetiology, prognosis, and diagnostic practices in this population. Future work should focus on replicating these findings in independent samples, and on the biological and/or psychosocial mechanisms underlying better global functioning in those who have high levels of both autistic and positive schizotypal traits.
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http://dx.doi.org/10.1016/j.jad.2016.09.059DOI Listing
January 2017

Genome-wide Association for Major Depression Through Age at Onset Stratification: Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium.

Biol Psychiatry 2017 02 24;81(4):325-335. Epub 2016 May 24.

Medical Genetics Section, Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom.

Background: Major depressive disorder (MDD) is a disabling mood disorder, and despite a known heritable component, a large meta-analysis of genome-wide association studies revealed no replicable genetic risk variants. Given prior evidence of heterogeneity by age at onset in MDD, we tested whether genome-wide significant risk variants for MDD could be identified in cases subdivided by age at onset.

Methods: Discovery case-control genome-wide association studies were performed where cases were stratified using increasing/decreasing age-at-onset cutoffs; significant single nucleotide polymorphisms were tested in nine independent replication samples, giving a total sample of 22,158 cases and 133,749 control subjects for subsetting. Polygenic score analysis was used to examine whether differences in shared genetic risk exists between earlier and adult-onset MDD with commonly comorbid disorders of schizophrenia, bipolar disorder, Alzheimer's disease, and coronary artery disease.

Results: We identified one replicated genome-wide significant locus associated with adult-onset (>27 years) MDD (rs7647854, odds ratio: 1.16, 95% confidence interval: 1.11-1.21, p = 5.2 × 10). Using polygenic score analyses, we show that earlier-onset MDD is genetically more similar to schizophrenia and bipolar disorder than adult-onset MDD.

Conclusions: We demonstrate that using additional phenotype data previously collected by genetic studies to tackle phenotypic heterogeneity in MDD can successfully lead to the discovery of genetic risk factor despite reduced sample size. Furthermore, our results suggest that the genetic susceptibility to MDD differs between adult- and earlier-onset MDD, with earlier-onset cases having a greater genetic overlap with schizophrenia and bipolar disorder.
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http://dx.doi.org/10.1016/j.biopsych.2016.05.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5262436PMC
February 2017

Prevalence and correlates of psychotic experiences amongst children of depressed parents.

Psychiatry Res 2016 Sep 8;243:81-6. Epub 2016 Mar 8.

Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, Wales, UK; School of Social and Community Medicine, University of Bristol, Bristol, UK. Electronic address:

Psychotic experiences in young people are substantially more common than psychotic disorders, and are associated with distress and functional impairment. Family history of depression as well as of schizophrenia increases risk for psychotic experiences, but the prevalence of such experiences and their clinical relevance in offspring of depressed parents is unknown. Our objectives were to explore i) the prevalence of psychotic experiences amongst offspring of parents with recurrent unipolar depression and ii) the relationship between psychotic experiences and other psychopathology. Data were drawn from the 'Early Prediction of Adolescent Depression' longitudinal study of high-risk offspring (aged 9-17 years at baseline) of 337 parents with recurrent depression. Three assessments were conducted over four years. Psychopathology was assessed using the Child and Adolescent Psychiatric Assessment. Seventy-eight percent of families (n=262) had complete data on psychotic experiences at each of the three time points. During the study, 8.4% (n=22; 95% CI 5.0%, 11.8%) of offspring reported psychotic experiences on at least one occasion, and these were associated with psychiatric disorder, specifically mood and disruptive disorders, and suicidal thoughts/behaviour. Psychotic experiences amongst offspring of depressed parents index a range of psychopathology. Further research is needed to examine their clinical significance and long-term consequences.
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http://dx.doi.org/10.1016/j.psychres.2016.03.012DOI Listing
September 2016