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Greater environmental sensitivity has been associated with increased risk of mental health problems, especially in response to stressors, and lower levels of subjective wellbeing. Conversely, sensitivity also correlates with lowerrisk of emotional problems in the absenceof adversity, and in response to positiveenvironmental influences. Additionally, sensitivity has been found to correlate positively with autistic traits. Individual differences in environmental sensitivity are partly heritable, but it is unknown to what extent the aetiological factors underlying sensitivity overlap with those on emotional problems (anxiety and depressive symptoms), autistic traits and wellbeing. The current study used multivariate twin models and data on sensitivity, emotional problems, autistic traits, and several indices of psychological and subjective wellbeing, from over 2800 adolescent twins in England and Wales. We found that greater overall sensitivity correlated with greater emotional problems, autistic traits, and lower subjective wellbeing. A similar pattern of correlations was found for the Excitation and Sensory factors of sensitivity, but, in contrast, the Aesthetic factor was positively correlated with psychological wellbeing, though not with emotional problems nor autistic traits. The observed correlations were largely due to overlapping genetic influences. Importantly, genetic influences underlying sensitivity explained between 2 and 12% of the variations in emotional problems, autistic traits, and subjective wellbeing, independentof trait-specific or overlapping genetic influences. These findings encourage incorporating the genetics of environmental sensitivity in future genomic studies aiming to delineate the heterogeneity in emotional problems, autistic traits, and wellbeing.

Genome-wide association studies (GWAS) provide biological insights into disease onset and progression and have potential to produce clinically useful biomarkers. A growing body of GWAS focuses on quantitative and transdiagnostic phenotypic targets, such as symptom severity or biological markers, to enhance gene discovery and the translational utility of genetic findings. The current review discusses such phenotypic approaches in GWAS across major psychiatric disorders. We identify themes and recommendations that emerge from the literature to date, including issues of sample size, reliability, convergent validity, sources of phenotypic information, phenotypes based on biological and behavioral markers such as neuroimaging and chronotype, and longitudinal phenotypes. We also discuss insights from multi-trait methods such as genomic structural equation modelling. These provide insight into how hierarchical ‘splitting’ and ‘lumping’ approaches can be applied to both diagnostic and dimensional phenotypes to model clinical heterogeneity and comorbidity. Overall, dimensional and transdiagnostic phenotypes have enhanced gene discovery in many psychiatric conditions and promises to yield fruitful GWAS targets in the years to come.

The Mood Disorder Questionnaire (MDQ) is a common screening tool for bipolar disorder that assesses manic symptoms. Its utility for genetic studies of mania or bipolar traits has not been fully examined. We psychometrically compared the MDQ to self‐reported bipolar disorder in participants from the United Kingdom National Institute of Health and Care Research Mental Health BioResource. We conducted genome‐wide association studies of manic symptom quantitative traits and symptom subgroups, derived from the MDQ items (N= 11,568–19,859). We calculated genetic correlations with bipolar disorder and other psychiatric and behavioral traits. The MDQ screener showed low positive predictive value (0.29) for self‐reported bipolar disorder. Neither concurrent nor lifetime manic symptoms were genetically correlated with bipolar disorder. Lifetime manic symptoms had a highest genetic correlation (rg= 1.0) with posttraumatic stress disorder although this was not confirmed by within‐cohort phenotypic correlations (rp= 0.41). Other significant genetic correlations included attention deficit hyperactivity disorder (rg= 0.69), insomnia (rg= 0.55), and major depressive disorder (rg= 0.42). Our study adds to existing literature questioning the MDQ's validity and suggests it may capture symptoms of general distress or psychopathology, rather than hypomania/mania specifically, in at‐risk populations.

Objective: Information about the psychiatric histories of adults with anxiety disorders was examined to further inform nosology and etiological/preventive efforts. Method: The authors used data from a prospective longitudinal study of a representative birth cohort (N=1,037) from ages 11 to 32 years, making psychiatric diagnoses according to DSM criteria. For adults with anxiety disorders at 32 years, follow-back analyses ascertained first diagnosis of anxiety and other juvenile disorders. Results: Of adults with each type of anxiety disorder, approximately half had been diagnosed with a psychiatric disorder (one-third with an anxiety disorder) by age 15. The juvenile histories of psychiatric problems for adults with different types of anxiety disorders were largely nonspecific, partially reflecting comorbidity at 32 years. Histories of anxiety and depression were most common. There was also specificity. For example, adults with panic disorder did not have histories of juvenile disorders, whereas those with other anxiety disorders did. Adults with posttraumatic stress disorder had histories of conduct disorder, whereas those with other anxiety disorders did not. Adults with specific phobia had histories of juvenile phobias but not other anxiety disorders. Conclusions: Strong comorbidity between different anxiety disorders and lack of specificity in developmental histories of adults with anxiety disorders supports a hierarchical approach to classification, with a broad class of anxiety disorders having individual disorders within it. The early first diagnosis of psychiatric difficulties in individuals with anxiety disorders suggests the need to target research examining the etiology of anxiety disorders and preventions early in life.

The requirement for large sample sizes for psychiatric genetic analyses necessitates novel approaches to derive cases. Anxiety and depression show substantial genetic overlap and share pharmacological treatments. Data on prescribed medication could be effective for inferring case status when other indicators of mental health are unavailable. We investigated self‐reported current medication use in UK Biobank participants of European ancestry. Medication Status cases reported using antidepressant or anxiolytic medication (n= 22,218), controls did not report psychotropic medication use (n= 168,959). A subset, “Medication Only,” additionally did not meet criteria for any other mental health indicator (case n= 2,643, control n= 107,029). We assessed genetic overlap between these phenotypes and two published genetic association studies of anxiety and depression, and an internalizing disorder trait derived from symptom‐based questionnaires in UK Biobank. Genetic correlations between Medication Status and the three anxiety and depression phenotypes were significant (rg= 0.60–0.73). In the Medication Only subset, the genetic correlation with depression was significant (rg= 0.51). The three polygenic scores explained 0.33% – 0.80% of the variance in Medication Status and 0.07% – 0.19% of the variance in Medication Only. This study provides evidence that self‐reported current medication use offers an alternate or supplementary anxiety or depression phenotype in genetic studies where diagnostic information is sparse or unavailable.

Genome-wide association (GWA) studies have uncovered DNA variants associated with individual differences in general cognitive ability (g), but these are far from capturing heritability estimates obtained from twin studies. A major barrier to finding more of this ‘missing heritability’ is assessment––the use of diverse measures across GWA studies as well as time and the cost of assessment. In a series of four studies, we created a 15-min (40-item), online, gamified measure of gthat is highly reliable (alpha = 0.78; two-week test-retest reliability = 0.88), psychometrically valid and scalable; we called this new measure Pathfinder. In a fifth study, we administered this measure to 4,751 young adults from the Twins Early Development Study. This novel gmeasure, which also yields reliable verbal and nonverbal scores, correlated substantially with standard measures of gcollected at previous ages (rranging from 0.42 at age 7 to 0.57 at age 16). Pathfinder showed substantial twin heritability (0.57, 95% CIs = 0.43, 0.68) and SNP heritability (0.37, 95% CIs = 0.04, 0.70). A polygenic score computed from GWA studies of five cognitive and educational traits accounted for 12% of the variation in g, the strongest DNA-based prediction of gto date. Widespread use of this engaging new measure will advance research not only in genomics but throughout the biological, medical, and behavioural sciences.

Anxiety disorders are common, complex psychiatric disorders with twin heritabilities of 30–60%. We conducted a genome-wide association study of Lifetime Anxiety Disorder (ncase?=?25 453, ncontrol?=?58 113) and an additional analysis of Current Anxiety Symptoms (ncase?=?19 012, ncontrol?=?58 113). The liability scale common variant heritability estimate for Lifetime Anxiety Disorder was 26%, and for Current Anxiety Symptoms was 31%. Five novel genome-wide significant loci were identified including an intergenic region on chromosome 9 that has previously been associated with neuroticism, and a locus overlapping the BDNFreceptor gene, NTRK2. Anxiety showed significant positive genetic correlations with depression and insomnia as well as coronary artery disease, mirroring findings from epidemiological studies. We conclude that common genetic variation accounts for a substantive proportion of the genetic architecture underlying anxiety.

Depression is more frequent among individuals exposed to traumatic events. Both trauma exposure and depression are heritable. However, the relationship between these traits, including the role of genetic risk factors, is complex and poorly understood. When modelling trauma exposure as an environmental influence on depression, both gene-environment correlations and gene-environment interactions have been observed. The UK Biobank concurrently assessed Major Depressive Disorder (MDD) and self-reported lifetime exposure to traumatic events in 126,522 genotyped individuals of European ancestry. We contrasted genetic influences on MDD stratified by reported trauma exposure (final sample size range: 24,094–92,957). The SNP-based heritability of MDD with reported trauma exposure (24%) was greater than MDD without reported trauma exposure (12%). Simulations showed that this is not confounded by the strong, positive genetic correlation observed between MDD and reported trauma exposure. We also observed that the genetic correlation between MDD and waist circumference was only significant in individuals reporting trauma exposure (rg= 0.24, p= 1.8 × 10−7versus rg= −0.05, p= 0.39 in individuals not reporting trauma exposure, difference p= 2.3 × 10−4). Our results suggest that the genetic contribution to MDD is greater when reported trauma is present, and that a complex relationship exists between reported trauma exposure, body composition, and MDD.

Differential DNA methylation of the hypothalamic‐pituitary‐adrenal axis related gene FKBP5has recently been shown to be associated with varying response to environmental influences and may play a role in how well people respond to psychological treatments. Participants (n= 111) received exposure‐based cognitive behavioural therapy (CBT) for agoraphobia with or without panic disorder, or specific phobias. Percentage DNA methylation levels were measured for the promoter region and intron 7 of FKBP5. The association between percentage reduction in clinical severity and change in DNA methylation was tested using linear mixed models. The effect of genotype (rs1360780) was tested by the inclusion of an interaction term. The association between change in DNA methylation and FKBP5expression was examined. Change in percentage DNA methylation at one CpG site of intron 7 was associated with percentage reduction in severity (β = −4.26, p= 3.90 × 10−4), where a decrease in DNA methylation was associated with greater response to therapy. An interaction was detected between rs1360780 and changes in DNA methylation in the promoter region of FKBP5on treatment outcome (p= .045) but did not survive correction for multiple testing. Changes in DNA methylation were not associated with FKBP5expression. Decreasing DNA methylation at one CpG site of intron 7 of FKBP5was strongly associated with decreasing anxiety severity following exposure‐based CBT. In addition, there was suggestive evidence that allele‐specific methylation at the promoter region may also be associated with treatment response. The results of this study add to the growing literature demonstrating the role of biological processes such as DNA methylation in response to environmental influences.

Major depressive disorder is a clinically heterogeneous psychiatric disorder with a polygenic architecture. Genome-wide association studies have identified a number of risk-associated variants across the genome and have reported growing evidence of NETRIN1 pathway involvement. Stratifying disease risk by genetic variation within the NETRIN1 pathway may provide important routes for identification of disease mechanisms by focusing on a specific process, excluding heterogeneous risk-associated variation in other pathways. Here, we sought to investigate whether major depressive disorder polygenic risk scores derived from the NETRIN1 signaling pathway (NETRIN1-PRSs) and the whole genome, excluding NETRIN1 pathway genes (genomic-PRSs), were associated with white matter microstructure.

Maternal prenatal depression is a known risk factor for early-life psychopathology among offspring; however, potential risk transmission mechanisms need to be distinguished. We aimed to test the relative importance of passive genetic transmission, direct exposure, and indirect exposure in the association between maternal prenatal depressive symptoms and early-life internalising and externalising psychopathology in offspring.

Emotion recognition is disrupted in many mental health disorders, which may reflect shared genetic aetiology between this trait and these disorders. We explored genetic influences on emotion recognition and the relationship between these influences and mental health phenotypes. Eight‐year‐old participants (n= 4,097) from the Avon Longitudinal Study of Parents and Children (ALSPAC) completed the Diagnostic Analysis of Non‐Verbal Accuracy (DANVA) faces test. Genome‐wide genotype data was available from the Illumina HumanHap550 Quad microarray. Genome‐wide association studies were performed to assess associations with recognition of individual emotions and emotion in general. Exploratory polygenic risk scoring was performed using published genomic data for schizophrenia, bipolar disorder, depression, autism spectrum disorder, anorexia, and anxiety disorders. No individual genetic variants were identified at conventional levels of significance in any analysis although several loci were associated at a level suggestive of significance. SNP‐chip heritability analyses did not identify a heritable component of variance for any phenotype. Polygenic scores were not associated with any phenotype. The effect sizes of variants influencing emotion recognition are likely to be small. Previous studies of emotion identification have yielded non‐zero estimates of SNP‐heritability. This discrepancy is likely due to differences in the measurement and analysis of the phenotype.

Extinction learning is an important mechanism in the successful psychological treatment of anxiety. Individual differences in response and relapse following Cognitive Behavior Therapy may in part be explained by variability in the ease with which fears are extinguished or the vulnerability of these fears to re‐emerge. Given the role of the endocannabinoid system in fear extinction, this study investigates whether genetic variation in the endocannabinoid system explains individual differences in response to CBT. Children (N = 1,309) with a primary anxiety disorder diagnosis were recruited. We investigated the relationship between variation in the CNR1, CNR2, and FAAH genes and change in primary anxiety disorder severity between pre‐ and post‐treatment and during the follow‐up period in the full sample and a subset with fear‐based anxiety disorder diagnoses. Change in symptom severity during active treatment was nominally associated (P < 0.05) with two SNPs. During the follow‐up period, five SNPs were nominally associated with a poorer treatment response (rs806365 [CNR1]; rs2501431 [CNR2]; rs2070956 [CNR2]; rs7769940 [CNR1]; rs2209172 [FAAH]) and one with a more favorable response (rs6928813 [CNR1]). Within the fear‐based subset, the effect of rs806365 survived multiple testing corrections (P < 0.0016). We found very limited evidence for an association between variants in endocannabinoid system genes and treatment response once multiple testing corrections were applied. Larger, more homogenous cohorts are needed to allow the identification of variants of small but statistically significant effect and to estimate effect sizes for these variants with greater precision in order to determine their potential clinical utility. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric GeneticsPublished by Wiley Periodicals, Inc.

Decades of research have shown that environmental exposures, including self-reports of trauma, are partly heritable. Heritable characteristics may influence exposure to and interpretations of environmental factors. Identifying heritable factors associated with self-reported trauma could improve our understanding of vulnerability to exposure and the interpretation of life events.

To estimate genetic and environmental influences on the associations between insomnia and depression symptoms concurrently and longitudinally.

Background: Alcohol use motives are closely associated with specific profiles of alcohol use and reflect a subjectively derived decisional framework based on a motivational style of responding. Adult twin studies typically estimate the heritability of alcohol use motives to be between 7 and 42%, although relatively little is known about genetic and environmental influences upon alcohol use motives in adolescence.

To examine the extent to which genetic and environmental factors influence components of sleep quality; the degree to which these components co-occur; and genetic and environmental influences on this co-occurrence.

To establish the direction and etiology of longitudinal associations between sleep problems and depression symptoms in children.

There are several reported associations between depressive disorders, panic disorder, and obsessive–compulsive disorder (OCD) and a variety of polymorphisms in the monoamine oxidase A (MAOA) gene. Associations have also been reported between the catechol-O-methyltransferase (COMT) gene and both OCD and bipolar depression. However, the role of these markers has not been explored for the personality trait of neuroticism (N), a normally distributed quantitative trait, which is highly genetically correlated with anxiety and depression and may be a vulnerability to either type of disorder. We explored the possible role of MAOA, COMT, and their interaction on N using a selected extremes design. From a sample of 2,085 individuals, each assessed for N by two independent peers rather than using self-report questionnaires, we selected 57 individuals from the top 10% of scores, and 62 individuals from the bottom 10%. Using selected extreme low subjects as the controls, rather than an unselected control group gives roughly twice the power of a standard case-control design. We typed a functional variable number tandem repeat (VNTR) in the MAOA gene promoter, and a functional polymorphism in the coding region of the COMT gene. Two novel alleles in the MAOA VNTR were identified on the basis of their size, and their structure examined by sequencing analysis. We found weak evidence for association with COMT genotype, when the females and males were considered separately, and for MAOA genotype in males only. There was no significant interaction between COMT and MAOA. © 2003 Wiley-Liss, Inc.

Developmental studies of antisocial behavior (ASB) have found two subgroups of behaviors, roughly described as aggressive and nonaggressive ASB. Theoretical accounts predict that aggressive ASB, which shows greater stability, should have high heritability. In contrast, nonaggressive ASB is very common in adolescence, shows less continuity, and should be influenced both by genes and shared environment. This study explored the genetic and environmental influences on aggressive and nonaggressive ASB in over 1,000 twin pairs aged 8–9 years and again at 13–14 years. Threshold models were fit to the data to incorporate the skew. In childhood, aggressive ASB was highly heritable and showed little influence of shared environment, whereas nonaggressive ASB was significantly influenced both by genes and shared environment. In adolescence, both variables were influenced both by genes and shared environment. The continuity in aggressive antisocial behavior symptoms from childhood to adolescence was largely mediated by genetic influences, whereas continuity in nonaggressive antisocial behavior was mediated both by the shared environment and genetic influences. These data are in agreement with the hypothesis that aggressive ASB is a stable heritable trait as compared to nonaggressive behavior, which is more strongly influenced by the environment and shows less genetic stability over time.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

POLYMORPHISMS in the serotonin transporter gene (5HTT) have been reported to be associated with neuroticism (emotionality) and with depression. A recent report of an association between 5HTT and neuroticism involved unselected samples and self-report questionnaires.1We attempted to extend these findings using a selected extremes design and peer ratings. From a sample of 2085 individuals, each assessed on neuroticism by two independent peers, we selected 52 individuals from the top 5 and 54 individuals from the bottom 5. No association was found for either a functional 44 bp insertion/deletion polymorphism in 5HTT regulatory sequence (5HTTLPR) or for a non-functional variable number tandem repeat 5HTT polymorphism.

Antidepressants are a first-line treatment for depression. However, only a third of individuals experience remission after the first treatment. Common genetic variation, in part, likely regulates antidepressant response, yet the success of previous genome-wide association studies has been limited by sample size. This study performs the largest genetic analysis of prospectively assessed antidepressant response in major depressive disorder to gain insight into the underlying biology and enable out-of-sample prediction.

BECAUSE general cognitive ability (g) is among the most heritable behavioural traits, it is a reasonable target for a search for quantitative trait loci (QTLs). We used a selected-extremes design to test candidate genes for allelic association with g. Polymorphisms in four genes in the dopamine system (DRD2, DRD3, DRD4, DAT1) were genotyped for 51 high gchildren with IQ scores > 130 and for 51 average gcontrol children. No significant allelic or genotypic differences were found between the high gand average ggroups for these markers of the dopamine system, even though the selected-extremes design provides power to detect QTL associations that involve a relative risk of about 1.5.