Trans-ethnic kidney function association study reveals putative causal genes and effects on kidney-specific disease aetiologies

Chronic kidney disease (CKD) affects ~10% of the global population, with considerable ethnic differences in prevalence and aetiology. We assemble genome-wide association studies of estimated glomerular filtration rate (eGFR), a measure of kidney function that defines CKD, in 312,468 individuals of diverse ancestry. We identify 127 distinct association signals with homogeneous effects on eGFR across ancestries and enrichment in genomic annotations including kidney-specific histone modifications. Fine-mapping reveals 40 high-confidence variants driving eGFR associations and highlights putative causal genes with cell-type specific expression in glomerulus, and in proximal and distal nephron. Mendelian randomisation supports causal effects of eGFR on overall and cause-specific CKD, kidney stone formation, diastolic blood pressure and hypertension. These results define novel molecular mechanisms and putative causal genes for eGFR, offering insight into clinical outcomes and routes to CKD treatment development.

Estimated glomerular filtration rate (eGFR) is a measure of kidney function used to define chronic kidney disease. Here, Morris et al. perform trans-ethnic genome-wide meta-analyses for eGFR in 312,468 individuals and identify novel loci and downstream putative causal genes.

Genetic Predisposition vs Individual-Specific Processes in the Association Between Psychotic-like Experiences and Cannabis Use

Importance

Previous research indicates that cannabis use is associated with psychotic-like experiences (PLEs). However, it is unclear whether this association results from predispositional (ie, shared genetic) factors or individual-specific factors (eg, causal processes, such as cannabis use leading to PLEs).

Objectives

To estimate genetic and environmental correlations between cannabis use and PLEs, and to examine PLEs in twin and nontwin sibling pairs discordant for exposure to cannabis use to disentangle predispositional from individual-specific effects.

Design, Setting, and Participants

In this cross-sectional analysis, diagnostic interviews and self-reported data were collected from 2 separate population-based samples of twin and nontwin sibling pairs. Data from the Human Connectome Project were collected between August 10, 2012, and September 29, 2015, and data from the Australian Twin Registry Cohort 3 (ATR3) were collected between August 1, 2005, and August 31, 2010. Data were analyzed between August 17, 2017, and July 6, 2018. The study included data from 1188 Human Connectome Project participants and 3486 ATR3 participants, totaling 4674 participants.

Main Outcomes and Measures

Three cannabis-involvement variables were examined: frequent use (ie, ≥100 times), a DSM-IV lifetime cannabis use disorder diagnosis, and current cannabis use. Genetic and environmental correlations between cannabis involvement and PLEs were estimated. Generalized linear mixed models examined PLE differences in twin and nontwin sibling pairs discordant for cannabis use.

Results

Among the 4674 participants, the mean (SD) age was 30.5 (3.2) years, and 2923 (62.5%) were female. Data on race/ethnicity were not included as a covariate owing to lack of variability within the ATR3 sample; among the 1188 participants in the Human Connectome Project, 875 (73.7%) were white. Psychotic-like experiences were associated with frequent cannabis use (β = 0.11; 95% CI, 0.08-0.14), cannabis use disorder (β = 0.13; 95% CI, 0.09-0.16), and current cannabis use (β = 0.07; 95% CI, 0.04-0.10) even after adjustment for covariates. Correlated genetic factors explained between 69.2% and 84.1% of this observed association. Within discordant pairs of twins/siblings (Npairs, 308-324), Psychotic-like experiences were more common in cannabis-exposed individuals compared with their relative who used cannabis to a lesser degree (β ≥ .23, P < .05; eg, frequent and infrequent cannabis-using relatives significantly differed, z = -5.41; P < .001).

Conclusions and Relevance

Despite the strong contribution of shared genetic factors, frequent and problem cannabis use also appears to be associated with PLEs via person-specific pathways. This study's findings suggest that policy discussions surrounding legalization should consider the influence of escalations in cannabis use on traitlike indices of vulnerability, such as PLEs, which could contribute to pervasive psychological and interpersonal burden.

Transancestral GWAS of alcohol dependence reveals common genetic underpinnings with psychiatric disorders

Liability to alcohol dependence (AD) is heritable, but little is known about its complex polygenic architecture or its genetic relationship with other disorders. To discover loci associated with AD and characterize the relationship between AD and other psychiatric and behavioral outcomes, we carried out the largest genome-wide association study to date of DSM-IV-diagnosed AD. Genome-wide data on 14,904 individuals with AD and 37,944 controls from 28 case-control and family-based studies were meta-analyzed, stratified by genetic ancestry (European, n = 46,568; African, n = 6,280). Independent, genome-wide significant effects of different ADH1B variants were identified in European (rs1229984; P = 9.8 × 10-13) and African ancestries (rs2066702; P = 2.2 × 10-9). Significant genetic correlations were observed with 17 phenotypes, including schizophrenia, attention deficit-hyperactivity disorder, depression, and use of cigarettes and cannabis. The genetic underpinnings of AD only partially overlap with those for alcohol consumption, underscoring the genetic distinction between pathological and nonpathological drinking behaviors.

Novel pleiotropic risk loci for melanoma and nevus density implicate multiple biological pathways

The total number of acquired melanocytic nevi on the skin is strongly correlated with melanoma risk. Here we report a meta-analysis of 11 nevus GWAS from Australia, Netherlands, UK, and USA comprising 52,506 individuals. We confirm known loci including MTAP, PLA2G6, and IRF4, and detect novel SNPs in KITLG and a region of 9q32. In a bivariate analysis combining the nevus results with a recent melanoma GWAS meta-analysis (12,874 cases, 23,203 controls), SNPs near GPRC5A, CYP1B1, PPARGC1B, HDAC4, FAM208B, DOCK8, and SYNE2 reached global significance, and other loci, including MIR146A and OBFC1, reached a suggestive level. Overall, we conclude that most nevus genes affect melanoma risk (KITLG an exception), while many melanoma risk loci do not alter nevus count. For example, variants in TERC and OBFC1 affect both traits, but other telomere length maintenance genes seem to affect melanoma risk only. Our findings implicate multiple pathways in nevogenesis.

Genome Analyses of >200,000 Individuals Identify 58 Loci for Chronic Inflammation and Highlight Pathways that Link Inflammation and Complex Disorders

C-reactive protein (CRP) is a sensitive biomarker of chronic low-grade inflammation and is associated with multiple complex diseases. The genetic determinants of chronic inflammation remain largely unknown, and the causal role of CRP in several clinical outcomes is debated. We performed two genome-wide association studies (GWASs), on HapMap and 1000 Genomes imputed data, of circulating amounts of CRP by using data from 88 studies comprising 204,402 European individuals. Additionally, we performed in silico functional analyses and Mendelian randomization analyses with several clinical outcomes. The GWAS meta-analyses of CRP revealed 58 distinct genetic loci (p < 5 × 10-8). After adjustment for body mass index in the regression analysis, the associations at all except three loci remained. The lead variants at the distinct loci explained up to 7.0% of the variance in circulating amounts of CRP. We identified 66 gene sets that were organized in two substantially correlated clusters, one mainly composed of immune pathways and the other characterized by metabolic pathways in the liver. Mendelian randomization analyses revealed a causal protective effect of CRP on schizophrenia and a risk-increasing effect on bipolar disorder. Our findings provide further insights into the biology of inflammation and could lead to interventions for treating inflammation and its clinical consequences.

Genome-wide association meta-analysis of age at first cannabis use

BACKGROUND AND AIMS

Cannabis is one of the most commonly used substances among adolescents and young adults. Earlier age at cannabis initiation is linked to adverse life outcomes, including multi-substance use and dependence. This study estimated the heritability of age at first cannabis use and identified associations with genetic variants.

METHODS

A twin-based heritability analysis using 8055 twins from three cohorts was performed. We then carried out a genome-wide association meta-analysis of age at first cannabis use in a discovery sample of 24 953 individuals from nine European, North American and Australian cohorts, and a replication sample of 3735 individuals.

RESULTS

The twin-based heritability for age at first cannabis use was 38% [95% confidence interval (CI) = 19-60%]. Shared and unique environmental factors explained 39% (95% CI = 20-56%) and 22% (95% CI = 16-29%). The genome-wide association meta-analysis identified five single nucleotide polymorphisms (SNPs) on chromosome 16 within the calcium-transporting ATPase gene (ATP2C2) at P < 5E-08. All five SNPs are in high linkage disequilibrium (LD) (r2  > 0.8), with the strongest association at the intronic variant rs1574587 (P = 4.09E-09). Gene-based tests of association identified the ATP2C2 gene on 16q24.1 (P = 1.33e-06). Although the five SNPs and ATP2C2 did not replicate, ATP2C2 has been associated with cocaine dependence in a previous study. ATP2B2, which is a member of the same calcium signalling pathway, has been associated previously with opioid dependence. SNP-based heritability for age at first cannabis use was non-significant.

CONCLUSION

Age at cannabis initiation appears to be moderately heritable in western countries, and individual differences in onset can be explained by separate but correlated genetic liabilities. The significant association between age of initiation and ATP2C2 is consistent with the role of calcium signalling mechanisms in substance use disorders.

The Impact of Traumatic Experiences on Risky Sexual Behaviors in Black and White Young Adult Women

BACKGROUND

Trauma exposure has been linked to risky sexual behavior (RSB), but few studies have examined the impact of distinct trauma types on RSB in one model or how the association with trauma and RSB may differ across race.

PURPOSE

The objective of the current study was to examine the contribution of trauma exposure types to RSB-substance-related RSB and partner-related RSB identified through factor analysis-in young Black and White adult women.

METHODS

We investigated the associations of multiple trauma types and RSB factor scores in participants from a general population sample of young adult female twins (n = 2,948). We examined the independent relationship between specific traumas and RSB, adjusting for substance use, psychopathology, and familial covariates. All pertinent constructs were coded positive only if they occurred before sexual debut.

RESULTS

In Black women, sexual abuse was significantly associated with substance-related and partner-related RSB, but retained significance only for partner-related RSB in a fully adjusted model. For White women, sexual abuse and physical abuse were associated with both RSB factors in the base and fully adjusted models. Witnessing injury or death was only associated with RSBs in base models. For both groups, initiating alcohol (for Black women), alcohol, or cannabis (for White women) before sexual debut (i.e., early exposure) was associated with the greatest increased odds of RSB.

CONCLUSIONS

Data highlight the contribution of prior sexual abuse to RSBs for both White and Black women, and of prior physical abuse to RSBs for White women. Findings have implications for intervention after physical and sexual abuse exposure to prevent RSB, and thus, potentially reduce sexually transmitted infection/human immunodeficiency virus infection and unintended pregnancy in young women.

GWAS of lifetime cannabis use reveals new risk loci, genetic overlap with psychiatric traits, and a causal influence of schizophrenia

Cannabis use is a heritable trait that has been associated with adverse mental health outcomes. In the largest genome-wide association study (GWAS) for lifetime cannabis use to date (N = 184,765), we identified eight genome-wide significant independent single nucleotide polymorphisms in six regions. All measured genetic variants combined explained 11% of the variance. Gene-based tests revealed 35 significant genes in 16 regions, and S-PrediXcan analyses showed that 21 genes had different expression levels for cannabis users versus nonusers. The strongest finding across the different analyses was CADM2, which has been associated with substance use and risk-taking. Significant genetic correlations were found with 14 of 25 tested substance use and mental health-related traits, including smoking, alcohol use, schizophrenia and risk-taking. Mendelian randomization analysis showed evidence for a causal positive influence of schizophrenia risk on cannabis use. Overall, our study provides new insights into the etiology of cannabis use and its relation with mental health.

Moderation of alcohol craving reactivity to drinking-related contexts by individual differences in alcohol sensitivity: An ecological investigation

Laboratory cue exposure investigations have demonstrated that, relative to drinkers who report a high sensitivity to the pharmacologic effects of alcohol, low-sensitivity (LS) drinkers show exaggerated neurocognitive and behavioral reactivity to alcohol-related stimuli. The current study extends this line of work by testing whether LS drinkers report stronger cravings for alcohol in daily life. Data were from an ecological momentary assessment study in which participants (N = 403 frequent drinkers) carried a palmtop computer for 21 days and responded to questions regarding drinking behavior, alcohol craving, mood states, and situational context. Initial analyses identified subjective states (positive and negative mood, cigarette craving) and contextual factors (bar-restaurant location, weekend, time of day, presence of friend, recent smoking) associated with elevated craving states during nondrinking moments. Effects for nearly all these craving correlates were moderated by individual differences in alcohol sensitivity, such that the associations between situational factors and current alcohol craving were larger among LS individuals (as determined by a questionnaire completed at baseline). Complementary idiographic analyses indicated that self-reported craving increased when the constellation of situational factors more closely resembled individuals' observed drinking situations. Again, this effect was moderated by alcohol sensitivity, with greater craving response increases among LS drinkers. The findings align with predictions generated from theory and laboratory cue exposure investigations and should encourage further study of craving and incentive processes in LS drinkers. (PsycINFO Database Record

A direct test of the diathesis-stress model for depression

The diathesis-stress theory for depression states that the effects of stress on the depression risk are dependent on the diathesis or vulnerability, implying multiplicative interactive effects on the liability scale. We used polygenic risk scores for major depressive disorder (MDD) calculated from the results of the most recent analysis from the Psychiatric Genomics Consortium as a direct measure of the vulnerability for depression in a sample of 5221 individuals from 3083 families. In the same we also had measures of stressful life events and social support and a depression symptom score, as well as DSM-IV MDD diagnoses for most individuals. In order to estimate the variance in depression explained by the genetic vulnerability, the stressors and their interactions, we fitted linear mixed models controlling for relatedness for the whole sample as well as stratified by sex. We show a significant interaction of the polygenic risk scores with personal life events (0.12% of variance explained, P-value=0.0076) contributing positively to the risk of depression. Additionally, our results suggest possible differences in the aetiology of depression between women and men. In conclusion, our findings point to an extra risk for individuals with combined vulnerability and high number of reported personal life events beyond what would be expected from the additive contributions of these factors to the liability for depression, supporting the multiplicative diathesis-stress model for this disease.

Cross-Cultural Comparison of Genetic and Cultural Transmission of Smoking Initiation Using an Extended Twin Kinship Model

BACKGROUND

Considerable evidence from twin and adoption studies indicates that genetic and shared environmental factors play a role in the initiation of smoking behavior. Although twin and adoption designs are powerful to detect genetic and environmental influences, they do not provide information on the processes of assortative mating and parent-offspring transmission and their contribution to the variability explained by genetic and/or environmental factors.

METHODS

We examined the role of genetic and environmental factors in individual differences for smoking initiation (SI) using an extended kinship design. This design allows the simultaneous testing of additive and non-additive genetic, shared and individual-specific environmental factors, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission, while also estimating the regression of the prevalence of SI on age. A dichotomous lifetime 'ever' smoking measure was obtained from twins and relatives in the 'Virginia 30,000' sample and the 'Australian 25,000'.

RESULTS

Results demonstrate that both genetic and environmental factors play a significant role in the liability to SI. Major influences on individual differences appeared to be additive genetic and unique environmental effects, with smaller contributions from assortative mating, shared sibling environment, twin environment, cultural transmission, and resulting genotype-environment covariance. Age regression of the prevalence of SI was significant. The finding of negative cultural transmission without dominance led us to investigate more closely two possible mechanisms for the lower parent-offspring correlations compared to the sibling and DZ twin correlations in subsets of the data: (1) age × gene interaction, and (2) social homogamy. Neither of the mechanism provided a significantly better explanation of the data.

CONCLUSIONS

This study showed significant heritability, partly due to assortment, and significant effects of primarily non-parental shared environment on liability to SI.

Extended Twin Study of Alcohol Use in Virginia and Australia

Drinking alcohol is a normal behavior in many societies, and prior studies have demonstrated it has both genetic and environmental sources of variation. Using two very large samples of twins and their first-degree relatives (Australia ≈ 20,000 individuals from 8,019 families; Virginia ≈ 23,000 from 6,042 families), we examine whether there are differences: (1) in the genetic and environmental factors that influence four interrelated drinking behaviors (quantity, frequency, age of initiation, and number of drinks in the last week), (2) between the twin-only design and the extended twin design, and (3) the Australian and Virginia samples. We find that while drinking behaviors are interrelated, there are substantial differences in the genetic and environmental architectures across phenotypes. Specifically, drinking quantity, frequency, and number of drinks in the past week have large broad genetic variance components, and smaller but significant environmental variance components, while age of onset is driven exclusively by environmental factors. Further, the twin-only design and the extended twin design come to similar conclusions regarding broad-sense heritability and environmental transmission, but the extended twin models provide a more nuanced perspective. Finally, we find a high level of similarity between the Australian and Virginian samples, especially for the genetic factors. The observed differences, when present, tend to be at the environmental level. Implications for the extended twin model and future directions are discussed.

Within-Family Effects of Smoking during Pregnancy on ADHD: the Importance of Phenotype

We sought to test within- and between- family associations of smoking during pregnancy (SDP) and attention deficit-hyperactivity disorder (ADHD) symptoms using a structured interview based on the conventional Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) symptoms and the Strengths and Weaknesses of ADHD-Symptoms and Normal-Behavior (SWAN) scale, which is a population based measure that grew out of the notion that an ADHD diagnosis exists on the extreme end of a continuum of normative behaviors and includes both above- and below- average performance on attention and activity. We used a sibling-comparison approach in a sample of 173 families including siblings aged 7-16 years (52% male) drawn from the state of Missouri, USA, wherein mothers smoked during one pregnancy but not the other. There was a within-family effect of smoking during pregnancy on SWAN hyperactivity/impulsivity and SWAN total ADHD behaviors. The associations between SDP and DSM-IV-based ADHD symptom dimensions as well as SWAN inattention were explained by familial confounds. These findings suggest that SDP exerts a potentially causal effect on increased ADHD hyperactive/impulsive behaviors and that this SDP effect is best captured when hyperactivity/impulsivity is assessed more normatively across the population, rather than specifically assessing problematic behaviors via DSM symptoms. Thus, any potentially causal effect of SDP on ADHD symptom dimensions may be restricted to hyperactive/impulsive behaviors rather than inattention, and normative, non-DSM-IV based behavioral measures may provide a more sensitive test of mechanisms of SDP-ADHD symptom associations, particularly in non-clinical samples.

Publisher Correction: Protein-altering variants associated with body mass index implicate pathways that control energy intake and expenditure in obesity

In the version of this article originally published, one of the two authors with the name Wei Zhao was omitted from the author list and the affiliations for both authors were assigned to the single Wei Zhao in the author list. In addition, the ORCID for Wei Zhao (Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA) was incorrectly assigned to author Wei Zhou. The errors have been corrected in the HTML and PDF versions of the article.

Publisher Correction: Protein-altering variants associated with body mass index implicate pathways that control energy intake and expenditure in obesity

In the published version of this paper, the name of author Emanuele Di Angelantonio was misspelled. This error has now been corrected in the HTML and PDF versions of the article.

Genome-wide association analyses identify 44 risk variants and refine the genetic architecture of major depression

Major depressive disorder (MDD) is a common illness accompanied by considerable morbidity, mortality, costs, and heightened risk of suicide. We conducted a genome-wide association meta-analysis based in 135,458 cases and 344,901 controls and identified 44 independent and significant loci. The genetic findings were associated with clinical features of major depression and implicated brain regions exhibiting anatomical differences in cases. Targets of antidepressant medications and genes involved in gene splicing were enriched for smaller association signal. We found important relationships of genetic risk for major depression with educational attainment, body mass, and schizophrenia: lower educational attainment and higher body mass were putatively causal, whereas major depression and schizophrenia reflected a partly shared biological etiology. All humans carry lesser or greater numbers of genetic risk factors for major depression. These findings help refine the basis of major depression and imply that a continuous measure of risk underlies the clinical phenotype.

Genome-wide association study identifies a novel locus for cannabis dependence

Despite moderate heritability, only one study has identified genome-wide significant loci for cannabis-related phenotypes. We conducted meta-analyses of genome-wide association study data on 2080 cannabis-dependent cases and 6435 cannabis-exposed controls of European descent. A cluster of correlated single-nucleotide polymorphisms (SNPs) in a novel region on chromosome 10 was genome-wide significant (lowest P=1.3E-8). Among the SNPs, rs1409568 showed enrichment for H3K4me1 and H3K427ac marks, suggesting its role as an enhancer in addiction-relevant brain regions, such as the dorsolateral prefrontal cortex and the angular and cingulate gyri. This SNP is also predicted to modify binding scores for several transcription factors. We found modest evidence for replication for rs1409568 in an independent cohort of African American (896 cases and 1591 controls; P=0.03) but not European American (EA; 781 cases and 1905 controls) participants. The combined meta-analysis (3757 cases and 9931 controls) indicated trend-level significance for rs1409568 (P=2.85E-7). No genome-wide significant loci emerged for cannabis dependence criterion count (n=8050). There was also evidence that the minor allele of rs1409568 was associated with a 2.1% increase in right hippocampal volume in an independent sample of 430 EA college students (fwe-P=0.008). The identification and characterization of genome-wide significant loci for cannabis dependence is among the first steps toward understanding the biological contributions to the etiology of this psychiatric disorder, which appears to be rising in some developed nations.

No Genetic Overlap Between Circulating Iron Levels and Alzheimer's Disease

Iron deposition in the brain is a prominent feature of Alzheimer's disease (AD). Recently, peripheral iron measures have also been shown to be associated with AD status. However, it is not known whether these associations are causal: do elevated or depleted iron levels throughout life have an effect on AD risk? We evaluate the effects of peripheral iron on AD risk using a genetic profile score approach by testing whether variants affecting iron, transferrin, or ferritin levels selected from GWAS meta-analysis of approximately 24,000 individuals are also associated with AD risk in an independent case-control cohort (n∼10,000). Conversely, we test whether AD risk variants from a GWAS meta-analysis of approximately 54,000 account for any variance in iron measures (n∼9,000). We do not identify a genetic relationship, suggesting that peripheral iron is not causal in the initiation of AD pathology.

Prenatal Exposure Effects on Early Adolescent Substance Use: Preliminary Evidence From a Genetically Informed Bayesian Approach

OBJECTIVE

Given the controversy surrounding the question of whether there are direct or causal effects of exposure to maternal smoking during pregnancy (SDP) on offspring outcomes such as substance use during the adolescent years, we sought to test, on a preliminary basis, within- and between-family associations of SDP and initiation of substance use early in adolescence (by age 15 years) using a discordant sibling design.

METHOD

We used a sibling-comparison approach in a sample of 173 families drawn from the state of Missouri, wherein mothers were discordant for smoking behaviors between two different pregnancies, to test for associations of SDP and initiation of substance use in a younger adolescent cohort. The discordant sibling comparison approach allows for disentangling familial effects from direct effects of SDP through the purposeful collection of data from siblings within the same family with differential exposure.

RESULTS

There were no between- or within-family effects of SDP on initiation of any type of substance use (alcohol, marijuana, smoking, and other drug classes), suggesting that SDP does not exert a direct effect on substance use in early adolescence.

CONCLUSIONS

Preliminary findings did not support an association of SDP and initiation of substance use in this younger adolescent sample. Studies such as this one can help build a body of evidence to explain whether associations of SDP and adolescent outcomes reflect a direct effect of SPD or may instead be attributable to familial confounders that are controlled in the discordant sibling design.

WISDM Primary and Secondary Dependence Motives: Associations With Smoking Rate, Craving, and Cigarette Effects in the Natural Environment

Introduction

The Wisconsin Inventory of Smoking Dependence Motives (WISDM) is a multidimensional measure of smoking motives that was developed to facilitate research aiming to refine the nomological network surrounding tobacco dependence. Recent evidence suggests that a composite of four subscales, termed the Primary Dependence Motives (PDM), may represent core features of advanced addiction, while the remaining nine subscales (Secondary Dependence Motives; SDM) represent instrumental motives for cigarette use that may be relevant at any stage of smoking.

Methods

A sample of 255 smokers (all regular alcohol users) participated in an ecological momentary assessment study in which they monitored smoking behavior and related experiences for 21 days. Multilevel regression analyses tested how PDM and SDM predicted daily smoking rate, cigarette craving, and appraisals of pleasure and relief of unpleasant feelings from smoking.

Results

When PDM and SDM were entered simultaneously, only PDM was related to daily cigarette count, and only SDM predicted reports of craving and relief from unpleasant feelings from smoking. SDM was associated with reports of greater pleasure from smoking and PDM was associated with lower pleasure ratings. The Fagerström Test for Nicotine Dependence (FTND) was related to daily smoking rate and craving, but WISDM composites contributed incremental prediction.

Conclusions

The findings confirm that PDM indexes heavier use that is relatively unrelated to immediate consequences of smoking. SDM is not uniquely related to smoking heaviness, but is associated with craving and reports of pleasure and relief of unpleasant feelings derived from smoking during ad lib use.

Implications

This study extends the evidence for the distinction between the WISDM PDM and SDM. PDM scores are associated with heavier smoking and are relatively unrelated to immediate consequences of smoking. SDM is more strongly related to craving and reports of smoking-derived pleasure and relief of unpleasant feelings during ongoing use in daily life.

Comparison of Characteristics of Female Drivers with Single and Multiple DUI Convictions

BACKGROUND

Women are increasingly involved in drunk driving and fatal crashes, yet except for the screening performed in criminal justice settings, little is known about their life context, psychiatric histories, and family backgrounds. This study describes a sample of women with histories of arrest for driving under the influence of alcohol (DUI) who were interviewed outside a criminal justice setting and contrasts women with single versus multiple DUI convictions.

METHODS

Women with recent documented histories of DUI participated in a study of women's health behaviors. Thirty-six women with 1 DUI and 62 with 2 or more DUIs participated in a diagnostic telephone interview which assessed demographics, alcohol use and problems, psychiatric problems, treatment, and partner violence.

RESULTS

The sample overall had high rates of co-occurring psychiatric problems, parental alcohol problems, early sexual and physical abuse, and head injuries. Alcohol use severity and the prevalence of head injuries and partner alcohol problems were significantly higher among women with multiple DUIs than women with a single DUI. Measures reflecting life context, such as marital status, number of children, and childhood trauma, were not associated with number of DUIs.

CONCLUSIONS

Findings suggest that DUI recidivism in women is accounted for primarily by AUD severity and is not influenced by previous life events such as partner violence, psychiatric problems, and family context such as divorce/separation or number of children. Multiple DUIs in women may mark an alcohol severity threshold beyond which few factors account for additional risk.

Interactive Effects of Maternal Alcohol Problems and Parental Separation on Timing of Daughter's First Drink

BACKGROUND

Few studies examine risk to offspring who experience both parental alcohol problems and parental separation and still fewer consider gender of the affected parent. We examined interactive effects of maternal versus paternal alcohol problems and parental separation on timing of first alcoholic drink in daughters.

METHODS

Data were drawn from a sample of 3,539 European (or other) ancestry (EA) and 611 African ancestry (AA) female twins born between 1975 and 1985, median age 15 at first assessment. Cox proportional hazards regression models were estimated predicting age at first full drink from parental history of alcohol problems (mother only, father only, or both parents), parental separation during childhood, and the interaction of parental alcohol problems and parental separation. Cox models were estimated without and with adjustment for correlated risk factors, separately for EA and AA twins.

RESULTS

For both EA and AA twins, a significant interaction between parental separation and mother-only alcohol problems was observed, suggesting reduced risk of drinking associated with mother-only alcohol problems in separated versus intact families.

CONCLUSIONS

Findings highlight parental separation as an important moderator of risk to children of mothers who have a history of problem drinking, with interactive effects observed consistently across racial group. To identify underlying processes, additional research is needed with more detailed characterization of separated families where mother only has a history of alcohol problems.

Effects of high alcohol intake, alcohol-related symptoms and smoking on mortality

BACKGROUND AND AIMS

Both high alcohol intake and alcohol dependence increase mortality, and both are associated with smoking. We aimed to compare the associations of quantity of alcohol, number of alcohol-related symptoms and smoking history with all-cause mortality, and to assess symptom count and smoking history as confounders or mediators of the effects of high alcohol intake.

DESIGN

Survival was analysed by Cox regression with sex, body mass index, alcohol intake (overall and by beverage), maximum drinks on any day, alcohol symptom count and smoking status as potential predictors of age at death.

SETTING

Australia.

PARTICIPANTS

Participants were apparently healthy volunteers consisting of 33 593 Australian adult twins and their relatives who completed questionnaires or interviews between 1979 and 2005.

MEASUREMENTS

Data on alcohol use, smoking and occurrence of symptoms related to alcohol use disorders and death records from the Australian National Death Index.

FINDINGS

A total of 3764 participants were matched with deaths occurring within Australia up to July 2014. Individually, alcohol intake [hazard ratio (HR) = 1.0082, 95% confidence interval (CI) = 1.0063-1.0102, per drink per week], beer intake (HR = 1.0159, 95% CI = 1.0123-1.0195, per drink per week), life-time maximum number of drinks in 1 day (HR = 1.0176, 95% CI = 1.0130-1.0221, per drink), symptom count (HR = 1.0867, 95% CI = 1.0633-1.1106, per symptom) and smoking status (HR = 2.82, 95% CI = 2.52-3.16 for smokers of 10+ cigarettes/day versus never-smokers) were each significant predictors of all-cause mortality. After adjustment for the independently significant predictors alcohol symptom count and smoking status, alcohol intake was no longer significant (adjusted HR = 1.0012 per drink per week, 95% CI = 0.9979-1.0145).

CONCLUSIONS

Number of symptoms related to high alcohol intake and tobacco smoking appear to account for the positive association between alcohol consumption and premature mortality.

Protein-altering variants associated with body mass index implicate pathways that control energy intake and expenditure in obesity

Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding variants from which pinpointing causal genes remains challenging. Here we combined data from 718,734 individuals to discover rare and low-frequency (minor allele frequency (MAF) < 5%) coding variants associated with BMI. We identified 14 coding variants in 13 genes, of which 8 variants were in genes (ZBTB7B, ACHE, RAPGEF3, RAB21, ZFHX3, ENTPD6, ZFR2 and ZNF169) newly implicated in human obesity, 2 variants were in genes (MC4R and KSR2) previously observed to be mutated in extreme obesity and 2 variants were in GIPR. The effect sizes of rare variants are ~10 times larger than those of common variants, with the largest effect observed in carriers of an MC4R mutation introducing a stop codon (p.Tyr35Ter, MAF = 0.01%), who weighed ~7 kg more than non-carriers. Pathway analyses based on the variants associated with BMI confirm enrichment of neuronal genes and provide new evidence for adipocyte and energy expenditure biology, widening the potential of genetically supported therapeutic targets in obesity.

Genome-Wide Association Studies of a Broad Spectrum of Antisocial Behavior

Importance

Antisocial behavior (ASB) places a large burden on perpetrators, survivors, and society. Twin studies indicate that half of the variation in this trait is genetic. Specific causal genetic variants have, however, not been identified.

Objectives

To estimate the single-nucleotide polymorphism-based heritability of ASB; to identify novel genetic risk variants, genes, or biological pathways; to test for pleiotropic associations with other psychiatric traits; and to reevaluate the candidate gene era data through the Broad Antisocial Behavior Consortium.

Design, Setting, and Participants

Genome-wide association data from 5 large population-based cohorts and 3 target samples with genome-wide genotype and ASB data were used for meta-analysis from March 1, 2014, to May 1, 2016. All data sets used quantitative phenotypes, except for the Finnish Crime Study, which applied a case-control design (370 patients and 5850 control individuals).

Main Outcome and Measures

This study adopted relatively broad inclusion criteria to achieve a quantitative measure of ASB derived from multiple measures, maximizing the sample size over different age ranges.

Results

The discovery samples comprised 16 400 individuals, whereas the target samples consisted of 9381 individuals (all individuals were of European descent), including child and adult samples (mean age range, 6.7-56.1 years). Three promising loci with sex-discordant associations were found (8535 female individuals, chromosome 1: rs2764450, chromosome 11: rs11215217; 7772 male individuals, chromosome X, rs41456347). Polygenic risk score analyses showed prognostication of antisocial phenotypes in an independent Finnish Crime Study (2536 male individuals and 3684 female individuals) and shared genetic origin with conduct problems in a population-based sample (394 male individuals and 431 female individuals) but not with conduct disorder in a substance-dependent sample (950 male individuals and 1386 female individuals) (R2 = 0.0017 in the most optimal model, P = 0.03). Significant inverse genetic correlation of ASB with educational attainment (r = -0.52, P = .005) was detected.

Conclusions and Relevance

The Broad Antisocial Behavior Consortium entails the largest collaboration to date on the genetic architecture of ASB, and the first results suggest that ASB may be highly polygenic and has potential heterogeneous genetic effects across sex.