ORCID Profile
0000-0002-3599-6018
Current Organisation
The University of Edinburgh
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Publisher: The Royal Society
Date: 07-07-2015
Abstract: Phenotypes expressed in a social context are not only a function of the in idual, but can also be shaped by the phenotypes of social partners. These social effects may play a major role in the evolution of cooperative breeding if social partners differ in the quality of care they provide and if in idual carers adjust their effort in relation to that of other carers. When applying social effects models to wild study systems, it is also important to explore sources of in idual plasticity that could masquerade as social effects. We studied offspring provisioning rates of parents and helpers in a wild population of long-tailed tits Aegithalos caudatus using a quantitative genetic framework to identify these social effects and partition them into genetic, permanent environment and current environment components. Controlling for other effects, in iduals were consistent in their provisioning effort at a given nest, but adjusted their effort based on who was in their social group, indicating the presence of social effects. However, these social effects differed between years and social contexts, indicating a current environment effect, rather than indicating a genetic or permanent environment effect. While this study reveals the importance of examining environmental and genetic sources of social effects, the framework we present is entirely general, enabling a greater understanding of potentially important social effects within any ecological population.
Publisher: Cold Spring Harbor Laboratory
Date: 05-07-2021
DOI: 10.1101/2021.06.30.21259731
Abstract: Depression is a disabling and highly prevalent condition where genetic and epigenetic differences, such as DNA methylation (DNAm), contribute to prediction of disease liability. We investigated the association between polygenic risk scores (PRS) for depression and DNAm by conducting a methylome-wide association study (MWAS) in Generation Scotland (N=8,898, mean age=49.8 years) with replication in the Lothian Birth Cohorts of 1921 and 1936 and adults in Avon Longitudinal Study of Parents and Children (ALSPAC) (N combined =2,049, mean age=79.1, 69.6 and 47.2 years, respectively). We also conducted a replication MWAS in the ALSPAC children (N=423, mean age=17.1 years). Wide-spread associations were found between PRS constructed using genetic risk variants for depression and DNAm in cytosine-guanine dinucleotide (CpG) probes that localised to genes involved in immune responses and neural development (N CpG =599, p Bonferroni .05, p .5×10 −8 ). The effect sizes for the significant associations were highly correlated between the discovery and replication s les in adults (r=0.83) and in adolescents (r=0.76). Additional analysis on the methylome-wide associations was conducted for each lead genetic risk variant. Over 40% of the independent genetic risk variants showed associations with CpG probe DNAm located in both the same ( cis ) and distal probes ( trans ) to the genetic loci (p Bonferroni .045). Subsequent Mendelian randomisation analysis showed that DNAm and depression are mutually causal (p FDR .039), and there is a greater number of causal effects found from DNAm to depression (DNAm to depression: p FDR ranged from 0.045 to 2.06×10 −120 depression to DNAm: p FDR ranged from 0.046 to 2.1×10 −23 ). Polygenic risk scores for depression, especially those constructed from genome-wide significant genetic risk variants, showed epigenome-wide methylation association differences in the methylome associated with immune responses and brain development. We also found evidence from Mendelian randomisation evidence that DNAm may be causal to depression, as well as a causal consequence of depression.
Publisher: Springer Science and Business Media LLC
Date: 30-08-2018
Publisher: Springer Science and Business Media LLC
Date: 30-03-2020
Publisher: Springer Science and Business Media LLC
Date: 08-05-2020
DOI: 10.1038/S41467-020-16022-0
Abstract: Depression is a leading cause of worldwide disability but there remains considerable uncertainty regarding its neural and behavioural associations. Here, using non-overlapping Psychiatric Genomics Consortium (PGC) datasets as a reference, we estimate polygenic risk scores for depression (depression-PRS) in a discovery ( N = 10,674) and replication ( N = 11,214) imaging s le from UK Biobank. We report 77 traits that are significantly associated with depression-PRS, in both discovery and replication analyses. Mendelian Randomisation analysis supports a potential causal effect of liability to depression on brain white matter microstructure ( β : 0.125 to 0.868, p FDR 0.043). Several behavioural traits are also associated with depression-PRS ( β : 0.014 to 0.180, p FDR : 0.049 to 1.28 × 10 −14 ) and we find a significant and positive interaction between depression-PRS and adverse environmental exposures on mental health outcomes. This study reveals replicable associations between depression-PRS and white matter microstructure. Our results indicate that white matter microstructure differences may be a causal consequence of liability to depression.
Publisher: Springer Science and Business Media LLC
Date: 18-05-2020
Publisher: Springer Science and Business Media LLC
Date: 08-01-2021
DOI: 10.1038/S41380-020-00987-X
Abstract: DNA methylation profiles of aggressive behavior may capture lifetime cumulative effects of genetic, stochastic, and environmental influences associated with aggression. Here, we report the first large meta-analysis of epigenome-wide association studies (EWAS) of aggressive behavior ( N = 15,324 participants). In peripheral blood s les of 14,434 participants from 18 cohorts with mean ages ranging from 7 to 68 years, 13 methylation sites were significantly associated with aggression (alpha = 1.2 × 10 −7 Bonferroni correction). In cord blood s les of 2425 children from five cohorts with aggression assessed at mean ages ranging from 4 to 7 years, 83% of these sites showed the same direction of association with childhood aggression ( r = 0.74, p = 0.006) but no epigenome-wide significant sites were found. Top-sites (48 at a false discovery rate of 5% in the peripheral blood meta-analysis or in a combined meta-analysis of peripheral blood and cord blood) have been associated with chemical exposures, smoking, cognition, metabolic traits, and genetic variation (mQTLs). Three genes whose expression levels were associated with top-sites were previously linked to schizophrenia and general risk tolerance. At six CpGs, DNA methylation variation in blood mirrors variation in the brain. On average 44% (range = 3–82%) of the aggression–methylation association was explained by current and former smoking and BMI. These findings point at loci that are sensitive to chemical exposures with potential implications for neuronal functions. We hope these results to be a starting point for studies leading to applications as peripheral biomarkers and to reveal causal relationships with aggression and related traits.
Publisher: F1000 Research Ltd
Date: 14-02-2018
DOI: 10.12688/WELLCOMEOPENRES.13893.1
Abstract: Background: Stressful life events (SLEs) and neuroticism are risk factors for major depressive disorder (MDD). However, SLEs and neuroticism are heritable and genetic risk for SLEs is correlated with risk for MDD. We sought to investigate the genetic and environmental contributions to SLEs in a family-based s le, and quantify genetic overlap with MDD and neuroticism. Methods: A subset of Generation Scotland: the Scottish Family Health Study (GS), consisting of 9618 in iduals with information on MDD, past 6 month SLEs, neuroticism and genome-wide genotype data was used in the present study. We estimated the heritability of SLEs using GCTA software. The environmental contribution to SLEs was assessed by modelling familial, couple and sibling components. Using polygenic risk scores (PRS) and LD score regression (LDSC) we analysed the genetic overlap between MDD, neuroticism and SLEs. Results: Past 6-month life events were positively correlated with lifetime MDD status (β=0.21, r 2 =1.1%, p=2.5 x 10 -25 ) and neuroticism (β =0.13, r 2 =1.9%, p=1.04 x 10 -37 ) at the phenotypic level. Common SNPs explained 8% of the phenotypic variance in personal life events (those directly affecting the in idual) (S.E.=0.03, p= 9 x 10 -4 ). A significant effect of couple environment was detected accounting for 13% (S.E.=0.03, p=0.016) of the phenotypic variation in SLEs. PRS analyses found that reporting more SLEs was associated with a higher polygenic risk for MDD (β =0.05, r 2 =0.3%, p=3 x 10 -5 ), but not a higher polygenic risk for neuroticism. LDSC showed a significant genetic correlation between SLEs and both MDD (r G =0.33, S.E.=0.08 ) and neuroticism (r G =0.15, S.E.=0.07). Conclusions: These findings suggest that SLEs should not be regarded solely as environmental risk factors for MDD as they are partially heritable and this heritability is shared with risk for MDD and neuroticism. Further work is needed to determine the causal direction and source of these associations.
Publisher: F1000 Research Ltd
Date: 16-07-2021
DOI: 10.12688/WELLCOMEOPENRES.15538.2
Abstract: STratifying Resilience and Depression Longitudinally (STRADL) is a population-based study built on the Generation Scotland: Scottish Family Health Study (GS:SFHS) resource. The aim of STRADL is to subtype major depressive disorder (MDD) on the basis of its aetiology, using detailed clinical, cognitive, and brain imaging assessments. The GS:SFHS provides an important opportunity to study complex gene-environment interactions, incorporating linkage to existing datasets and inclusion of early-life variables for two longitudinal birth cohorts. Specifically, data collection in STRADL included: socio-economic and lifestyle variables physical measures questionnaire data that assesses resilience, early-life adversity, personality, psychological health, and lifetime history of mood disorder laboratory s les cognitive tests and brain magnetic resonance imaging. Some of the questionnaire and cognitive data were first assessed at the GS:SFHS baseline assessment between 2006-2011, thus providing longitudinal measures relevant to the study of depression, psychological resilience, and cognition. In addition, routinely collected historic NHS data and early-life variables are linked to STRADL data, further providing opportunities for longitudinal analysis. Recruitment has been completed and we consented and tested 1,188 participants.
Publisher: Springer Science and Business Media LLC
Date: 16-04-2018
DOI: 10.1038/S41467-018-03819-3
Abstract: Depression is a polygenic trait that causes extensive periods of disability. Previous genetic studies have identified common risk variants which have progressively increased in number with increasing s le sizes of the respective studies. Here, we conduct a genome-wide association study in 322,580 UK Biobank participants for three depression-related phenotypes: broad depression, probable major depressive disorder (MDD), and International Classification of Diseases (ICD, version 9 or 10)-coded MDD. We identify 17 independent loci that are significantly associated ( P 5 × 10 −8 ) across the three phenotypes. The direction of effect of these loci is consistently replicated in an independent s le, with 14 loci likely representing novel findings. Gene sets are enriched in excitatory neurotransmission, mechanosensory behaviour, post synapse, neuron spine and dendrite functions. Our findings suggest that broad depression is the most tractable UK Biobank phenotype for discovering genes and gene sets that further our understanding of the biological pathways underlying depression.
Publisher: Springer Science and Business Media LLC
Date: 15-11-2021
Publisher: Springer Science and Business Media LLC
Date: 04-02-2019
Publisher: Cold Spring Harbor Laboratory
Date: 07-07-2023
DOI: 10.1101/2023.07.05.23292214
Abstract: Diagnostic criteria for major depressive disorder allow for heterogeneous symptom profiles but genetic analysis of major depressive symptoms has the potential to identify clinical and aetiological subtypes. There are several challenges to integrating symptom data from genetically-informative cohorts, such as s le size differences between clinical and community cohorts and various patterns of missing data. We conducted genome-wide association studies of major depressive symptoms in three clinical cohorts that were enriched for affected participants (Psychiatric Genomics Consortium, Australian Genetics of Depression Study, Generation Scotland) and three community cohorts (Avon Longitudinal Study of Parents and Children, Estonian Biobank, and UK Biobank). We fit a series of confirmatory factor models with factors that accounted for how symptom data was s led and then compared alternative models with different symptom factors. The best fitting model had a distinct factor for Appetite/Weight symptoms and an additional measurement factor that accounted for missing data patterns in the community cohorts (use of Depression and Anhedonia as gating symptoms). The results show the importance of assessing the directionality of symptoms (such as hypersomnia versus insomnia) and of accounting for study and measurement design when meta-analysing genetic association data.
Publisher: Cold Spring Harbor Laboratory
Date: 12-01-2018
DOI: 10.1101/247353
Abstract: Depression is more frequently observed among in iduals exposed to traumatic events. The relationship between trauma exposure and depression, including the role of genetic variation, is complex and poorly understood. The UK Biobank concurrently assessed depression and reported trauma exposure in 126,522 genotyped in iduals of European ancestry. We compared the shared aetiology of depression and a range of phenotypes, contrasting in iduals reporting trauma exposure with those who did not (final s le size range: 24,094-92,957). Depression was heritable in participants reporting trauma exposure and in unexposed in iduals, and the genetic correlation between the groups was substantial and not significantly different from 1. Genetic correlations between depression and psychiatric traits were strong regardless of reported trauma exposure, whereas genetic correlations between depression and body mass index (and related phenotypes) were observed only in trauma exposed in iduals. The narrower range of genetic correlations in trauma unexposed depression and the lack of correlation with BMI echoes earlier ideas of endogenous depression.
Publisher: Royal College of Psychiatrists
Date: 25-08-2021
DOI: 10.1192/BJP.2021.102
Abstract: Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools. To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics. Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO ( n = 12 977) and PAO ( n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication s le ( n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts. Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO. AAO and PAO are associated with indicators of bipolar disorder severity. In iduals 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.
Publisher: Proceedings of the National Academy of Sciences
Date: 31-10-2016
Abstract: In iduals with more education tend to live longer. Genetic variants have been discovered that predict educational attainment. We tested whether a “polygenic score” based on these genetic variants could make predictions about people’s lifespan. We used data from three cohort studies (including ,000 participants) to examine the link between offspring polygenic score for education and parental longevity. Across the studies, we found that participants with more education-linked genetic variants had longer-living parents compared with those with the lowest genetic education scores, those with the highest scores had parents who lived on average 6 months longer. This finding suggests the hypothesis that part of the ultimate explanation for the extended longevity of better-educated people is an underlying, quantifiable, genetic propensity.
Publisher: Springer Science and Business Media LLC
Date: 29-09-2021
Publisher: Springer Science and Business Media LLC
Date: 12-04-2016
DOI: 10.1038/MP.2016.49
Abstract: Neuroticism is a personality trait of fundamental importance for psychological well-being and public health. It is strongly associated with major depressive disorder (MDD) and several other psychiatric conditions. Although neuroticism is heritable, attempts to identify the alleles involved in previous studies have been limited by relatively small s le sizes. Here we report a combined meta-analysis of genome-wide association study (GWAS) of neuroticism that includes 91 370 participants from the UK Biobank cohort, 6659 participants from the Generation Scotland: Scottish Family Health Study (GS:SFHS) and 8687 participants from a QIMR (Queensland Institute of Medical Research) Berghofer Medical Research Institute (QIMR) cohort. All participants were assessed using the same neuroticism instrument, the Eysenck Personality Questionnaire-Revised (EPQ-R-S) Short Form’s Neuroticism scale. We found a single-nucleotide polymorphism-based heritability estimate for neuroticism of ∼15% (s.e.=0.7%). Meta-analysis identified nine novel loci associated with neuroticism. The strongest evidence for association was at a locus on chromosome 8 ( P =1.5 × 10 −15 ) spanning 4 Mb and containing at least 36 genes. Other associated loci included interesting candidate genes on chromosome 1 ( GRIK3 ( glutamate receptor ionotropic kainate 3 )), chromosome 4 ( KLHL2 ( Kelch-like protein 2 )), chromosome 17 ( CRHR1 ( corticotropin-releasing hormone receptor 1 ) and MAPT ( microtubule-associated protein Tau )) and on chromosome 18 ( CELF4 ( CUGBP elav-like family member 4 )). We found no evidence for genetic differences in the common allelic architecture of neuroticism by sex. By comparing our findings with those of the Psychiatric Genetics Consortia, we identified a strong genetic correlation between neuroticism and MDD and a less strong but significant genetic correlation with schizophrenia, although not with bipolar disorder. Polygenic risk scores derived from the primary UK Biobank s le captured ∼1% of the variance in neuroticism in the GS:SFHS and QIMR s les, although most of the genome-wide significant alleles identified within a UK Biobank-only GWAS of neuroticism were not independently replicated within these cohorts. The identification of nine novel neuroticism-associated loci will drive forward future work on the neurobiology of neuroticism and related phenotypes.
Publisher: Springer Science and Business Media LLC
Date: 18-01-2019
DOI: 10.1038/S41398-018-0356-7
Abstract: Depression has well-established influences from genetic and environmental risk factors. This has led to the diathesis-stress theory, which assumes a multiplicative gene-by-environment interaction (GxE) effect on risk. Recently, Colodro-Conde et al . empirically tested this theory, using the polygenic risk score for major depressive disorder (PRS, genes) and stressful life events (SLE, environment) effects on depressive symptoms, identifying significant GxE effects with an additive contribution to liability. We have tested the diathesis-stress theory on an independent s le of 4919 in iduals. We identified nominally significant positive GxE effects in the full cohort ( R 2 = 0.08%, p = 0.049) and in women ( R 2 = 0.19%, p = 0.017), but not in men ( R 2 = 0.15%, p = 0.07). GxE effects were nominally significant, but only in women, when SLE were split into those in which the respondent plays an active or passive role ( R 2 = 0.15%, p = 0.038 R 2 = 0.16%, p = 0.033, respectively). High PRS increased the risk of depression in participants reporting high numbers of SLE ( p = 2.86 × 10 −4 ). However, in those participants who reported no recent SLE, a higher PRS appeared to increase the risk of depressive symptoms in men ( β = 0.082, p = 0.016) but had a protective effect in women ( β = −0.061, p = 0.037). This difference was nominally significant ( p = 0.017). Our study reinforces the evidence of additional risk in the aetiology of depression due to GxE effects. However, larger s le sizes are required to robustly validate these findings.
Publisher: Cold Spring Harbor Laboratory
Date: 28-10-2023
Publisher: Cold Spring Harbor Laboratory
Date: 11-10-2018
DOI: 10.1101/440735
Abstract: Minimal phenotyping refers to the reliance on the use of a small number of self-report items for disease case identification. This strategy has been applied to genome-wide association studies (GWAS) of major depressive disorder (MDD). Here we report that the genotype derived heritability (h 2 SNP ) of depression defined by minimal phenotyping (14%, SE = 0.8%) is lower than strictly defined MDD (26%, SE = 2.2%). This cannot be explained by differences in prevalence between definitions or including cases of lower liability to MDD in minimal phenotyping definitions of depression, but can be explained by misdiagnosis of those without depression or with related conditions as cases of depression. Depression defined by minimal phenotyping is as genetically correlated with strictly defined MDD (rG = 0.81, SE = 0.03) as it is with the personality trait neuroticism (rG = 0.84, SE = 0.05), a trait not defined by the cardinal symptoms of depression. While they both show similar shared genetic liability with neuroticism, a greater proportion of the genome contributes to the minimal phenotyping definitions of depression (80.2%, SE = 0.6%) than to strictly defined MDD (65.8%, SE = 0.6%). We find that GWAS loci identified in minimal phenotyping definitions of depression are not specific to MDD: they also predispose to other psychiatric conditions. Finally, while highly predictive polygenic risk scores can be generated from minimal phenotyping definitions of MDD, the predictive power can be explained entirely by the s le size used to generate the polygenic risk score, rather than specificity for MDD. Our results reveal that genetic analysis of minimal phenotyping definitions of depression identifies non-specific genetic factors shared between MDD and other psychiatric conditions. Reliance on results from minimal phenotyping for MDD may thus bias views of the genetic architecture of MDD and may impede our ability to identify pathways specific to MDD.
Publisher: Cambridge University Press (CUP)
Date: 21-09-2022
DOI: 10.1017/S0033291722002720
Abstract: Major depressive disorder (MDD) was previously associated with negative affective biases. Evidence from larger population-based studies, however, is lacking, including whether biases normalise with remission. We investigated associations between affective bias measures and depressive symptom severity across a large community-based s le, followed by examining differences between remitted in iduals and controls. Participants from Generation Scotland ( N = 1109) completed the: (i) Bristol Emotion Recognition Task (BERT), (ii) Face Affective Go/No-go (FAGN), and (iii) Cambridge Gambling Task (CGT). In iduals were classified as MDD-current ( n = 43), MDD-remitted ( n = 282), or controls ( n = 784). Analyses included using affective bias summary measures (primary analyses), followed by detailed emotion/condition analyses of BERT and FAGN (secondary analyses). For summary measures, the only significant finding was an association between greater symptoms and lower risk adjustment for CGT across the s le (in iduals with greater symptoms were less likely to bet more, despite increasingly favourable conditions). This was no longer significant when controlling for non-affective cognition. No differences were found for remitted-MDD v. controls. Detailed analysis of BERT and FAGN indicated subtle negative biases across multiple measures of affective cognition with increasing symptom severity, that were independent of non-effective cognition [e.g. greater tendency to rate faces as angry (BERT), and lower accuracy for happy/neutral conditions (FAGN)]. Results for remitted-MDD were inconsistent. This suggests the presence of subtle negative affective biases at the level of emotion/condition in association with depressive symptoms across the s le, over and above those accounted for by non-affective cognition, with no evidence for affective biases in remitted in iduals.
Publisher: Public Library of Science (PLoS)
Date: 20-12-2018
Publisher: Cold Spring Harbor Laboratory
Date: 09-10-2018
DOI: 10.1101/433367
Abstract: Major depression is a debilitating psychiatric illness that is typically associated with low mood, anhedonia and a range of comorbidities. Depression has a heritable component that has remained difficult to elucidate with current s le sizes due to the polygenic nature of the disorder. To maximise s le size, we meta-analysed data on 807,553 in iduals (246,363 cases and 561,190 controls) from the three largest genome-wide association studies of depression. We identified 102 independent variants, 269 genes, and 15 gene-sets associated with depression, including both genes and gene-pathways associated with synaptic structure and neurotransmission. Further evidence of the importance of prefrontal brain regions in depression was provided by an enrichment analysis. In an independent replication s le of 1,306,354 in iduals (414,055 cases and 892,299 controls), 87 of the 102 associated variants were significant following multiple testing correction. Based on the putative genes associated with depression this work also highlights several potential drug repositioning opportunities. These findings advance our understanding of the complex genetic architecture of depression and provide several future avenues for understanding aetiology and developing new treatment approaches.
Publisher: Cambridge University Press (CUP)
Date: 02-10-2019
DOI: 10.1017/S0033291719002629
Abstract: Major depressive disorder and neuroticism (Neu) share a large genetic basis. We sought to determine whether this shared basis could be decomposed to identify genetic factors that are specific to depression. We analysed summary statistics from genome-wide association studies (GWAS) of depression (from the Psychiatric Genomics Consortium, 23andMe and UK Biobank) and compared them with GWAS of Neu (from UK Biobank). First, we used a pairwise GWAS analysis to classify variants as associated with only depression, with only Neu or with both. Second, we estimated partial genetic correlations to test whether the depression's genetic link with other phenotypes was explained by shared overlap with Neu. We found evidence that most genomic regions (25/37) associated with depression are likely to be shared with Neu. The overlapping common genetic variance of depression and Neu was genetically correlated primarily with psychiatric disorders. We found that the genetic contributions to depression, that were not shared with Neu, were positively correlated with metabolic phenotypes and cardiovascular disease, and negatively correlated with the personality trait conscientiousness. After removing shared genetic overlap with Neu, depression still had a specific association with schizophrenia, bipolar disorder, coronary artery disease and age of first birth. Independent of depression, Neu had specific genetic correlates in ulcerative colitis, pubertal growth, anorexia and education. Our findings demonstrate that, while genetic risk factors for depression are largely shared with Neu, there are also non-Neu-related features of depression that may be useful for further patient or phenotypic stratification.
Publisher: Springer Science and Business Media LLC
Date: 26-11-2018
Publisher: Springer Science and Business Media LLC
Date: 24-05-2020
DOI: 10.1038/S41398-020-0848-0
Abstract: Depression is a common and clinically heterogeneous mental health disorder that is frequently comorbid with other diseases and conditions. Stratification of depression may align sub-diagnoses more closely with their underling aetiology and provide more tractable targets for research and effective treatment. In the current study, we investigated whether genetic data could be used to identify subgroups within people with depression using the UK Biobank. Examination of cross-locus correlations were used to test for evidence of subgroups using genetic data from seven other complex traits and disorders that were genetically correlated with depression and had sufficient power ( .6) for detection. We found no evidence for subgroups within depression for schizophrenia, bipolar disorder, attention deficit/hyperactivity disorder, autism spectrum disorder, anorexia nervosa, inflammatory bowel disease or obesity. This suggests that for these traits, genetic correlations with depression were driven by pleiotropic genetic variants carried by everyone rather than by a specific subgroup.
Publisher: Cold Spring Harbor Laboratory
Date: 12-03-0044
DOI: 10.1101/2021.03.10.21253201
Abstract: The environment and events that we are exposed to in utero, during birth and in early childhood influence our future physical and mental health. The underlying mechanisms that lead to these outcomes in adulthood are unclear, but long-term changes in epigenetic marks, such as DNA methylation, could act as a mediating factor or biomarker. DNA methylation data was assayed at 713,522 CpG sites from 9,537 participants of the Generation Scotland: Scottish Family Health Study, a family-based cohort with extensive data on genetic, medical, family history and lifestyle information. Methylome-wide association studies of eight early life environment phenotypes and two adult mental health phenotypes were conducted using DNA methylation data collected from adult whole blood s les. Two genes involved with different developmental pathways (PRICKLE2 and ABI1) were annotated to CpG sites associated with preterm birth (P 1.27 × 10 −9 ). A further two genes important to the development of sensory pathways (SOBP and RPGRIP1) were annotated to sites associated with low birth weight (P 4.35 × 10 −8 ). Genes and gene-sets annotated from associated CpGs sites and methylation profile scores were then used to quantify any overlap between the early life environment and mental health traits. However, there was no evidence of any overlap after applying a correction for multiple testing. Time of year of birth was found to be associated with a significant difference in estimated lymphocyte and neutrophil counts. Early life environments influence the risk of developing mental health disorders later in life however, this study provides no evidence that this is mediated by stable changes to the methylome detectable in peripheral blood.
Publisher: Cold Spring Harbor Laboratory
Date: 16-04-2021
DOI: 10.1101/2021.04.16.21251163
Abstract: Studying the phenotypic and genetic characteristics of age and polarity at onset (AAO, PAO) in bipolar disorder (BD) can provide new insights into disease pathology and facilitate the development of screening tools. To examine the genetic architecture of AAO and PAO and their association with BD disease characteristics. Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (N=12977) and PAO (N=6773) were conducted in BD patients of 34 cohorts and a replication s le (N=2237). The association of onset with disease characteristics was investigated in two of these cohorts. Earlier AAO was associated with an increased risk of psychotic symptoms, suicidality, and fewer episodes. A depressive onset correlated with lifetime suicidality and a manic onset with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in SNV-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased polygenic scores for autism spectrum disorder (β=-0.34 years, SE=0.08), major depression (β=-0.34 years, SE=0.08), schizophrenia (β=-0.39 years, SE=0.08), and educational attainment (β=-0.31 years, SE=0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO. AAO and PAO are associated with indicators of BD severity. In iduals 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. In the largest study to systematically characterize age at onset (N=12977) and polarity at onset (N=6773) in bipolar disorder, we describe an association between illness onset characteristics and indicators of severity, confirming their clinical relevance. Our study shows that that early illness onset is associated with genetic liability for a broad range of psychiatric disorders. However, we also highlight systematic differences in age at onset across cohorts, continents, and phenotype definitions. This heterogeneity results in reduced heritability and affects genetic analyses, underscoring the need for the development of standardized phenotype definitions.
Publisher: Cold Spring Harbor Laboratory
Date: 05-08-2019
DOI: 10.1101/19001214
Abstract: This paper corrects and updates a paper published in BJPsych Open 2018 “Mental Health in UK Biobank” ( 0.1192/bjo.2018.12 ) that was voluntarily retracted following the finding of errors in the coding of the variable for alcohol use disorder. Notably, the percentage of participants reaching threshold for alcohol use disorder on the Alcohol Use Disorder Identification Tool increased from 7% to 21%. UK Biobank is a well-characterised cohort of over 500,000 participants that offers unique opportunities to investigate multiple diseases and risk factors. An online mental health questionnaire completed by UK Biobank participants expands the potential for research into mental disorders. An expert working group designed the questionnaire, using established measures where possible, and consulting with a service user group regarding acceptability. Operational criteria were agreed for defining likely disorder and risk states, including lifetime depression, mania/hypomania, generalised anxiety disorder, unusual experiences and self-harm, and current post-traumatic stress and alcohol use disorders. 157,366 completed online questionnaires were available by August 2017. Comparison of self-reported diagnosed mental disorder with a contemporary study shows a similar prevalence, despite respondents being of higher average socioeconomic status. Lifetime depression was the most common finding in 24% of participants (37,434), with current alcohol use disorder criteria met by 21% (32,602), while other criteria were met by less than 8% of the participants. There was extensive comorbidity among the syndromes. Mental disorders were associated with a high neuroticism score, adverse life events and long-term illness addiction and bipolar affective disorder in particular were associated with measures of deprivation. The questionnaire represents a very large mental health survey in itself, and the results presented here show high face validity, although caution is needed due to selection bias. Built into UK Biobank, these data intersect with other health data to offer unparalleled potential for crosscutting biomedical research involving mental health.
Publisher: Wiley
Date: 03-02-2011
DOI: 10.1111/J.1420-9101.2010.02212.X
Abstract: By determining access to limited resources, social dominance is often an important determinant of fitness. Thus, if heritable, standard theory predicts mean dominance should evolve. However, dominance is usually inferred from the tendency to win contests, and given one winner and one loser in any dyadic contest, the mean proportion won will always equal 0.5. Here, we argue that the apparent conflict between quantitative genetic theory and common sense is resolved by recognition of indirect genetic effects (IGEs). We estimate selection on, and genetic (co)variance structures for, social dominance, in a wild population of red deer Cervus elaphus, on the Scottish island of Rum. While dominance is heritable and positively correlated with lifetime fitness, contest outcomes depend as much on the genes carried by an opponent as on the genotype of a focal in idual. We show how this dependency imposes an absolute evolutionary constraint on the phenotypic mean, thus reconciling theoretical predictions with common sense. More generally, we argue that IGEs likely provide a widespread but poorly recognized source of evolutionary constraint for traits influenced by competition.
Publisher: Cold Spring Harbor Laboratory
Date: 05-05-2017
DOI: 10.1101/134601
Abstract: Depression is a common and clinically heterogeneous mental health disorder that is frequently comorbid with other diseases and conditions. Stratification of depression may align sub-diagnoses more closely with their underling aetiology and provide more tractable targets for research and effective treatment. In the current study, we investigated whether genetic data could be used to identify subgroups within people with depression using the UK Biobank. Examination of cross-locus correlations was used to test for evidence of subgroups by examining whether there was clustering of independent genetic variants associated with eleven other complex traits and disorders in people with depression. We found evidence of a subgroup within depression using age of natural menopause variants ( P = 1.69 × 10 −3 ) and this effect remained significant in females ( P = 1.18 × 10 −3 ), but not males ( P = 0.186). However, no evidence for this subgroup ( P 0.05) was found in Generation Scotland, iPSYCH, a UK Biobank replication cohort or the GERA cohort. In the UK Biobank, having depression was also associated with a later age of menopause (beta = 0.34, standard error = 0.06, P = 9.92 × 10 −8 ). A potential age of natural menopause subgroup within depression and the association between depression and a later age of menopause suggests that they partially share a developmental pathway.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Mark James Adams.