Spousal concordance for alcohol dependence: evidence for assortative mating or spousal interaction effects?

The impact of assortative mating, participation bias and socioeconomic status on the polygenic risk of behavioural and psychiatric traits

To investigate assortative mating (AM), participation bias and socioeconomic status (SES) with respect to the genetics of behavioural and psychiatric traits, we estimated AM signatures using gametic phase disequilibrium and within-spouses and within-siblings polygenic risk score correlation analyses, also performing a SES conditional analysis. The cross-method meta-analysis identified AM genetic signatures for multiple alcohol-related phenotypes, bipolar disorder, major depressive disorder, schizophrenia and Tourette syndrome. Here, after SES conditioning, we observed changes in the AM genetic signatures for maximum habitual alcohol intake, frequency of drinking alcohol and Tourette syndrome. We also observed significant gametic phase disequilibrium differences between UK Biobank mental health questionnaire responders versus non-responders for major depressive disorder and alcohol use disorder. These results highlight the impact of AM, participation bias and SES on the polygenic risk of behavioural and psychiatric traits, particularly in alcohol-related traits.

Correlations in sleeping patterns and circadian preference between spouses

Spouses may affect each other's sleeping behaviour. In 47,420 spouse-pairs from the UK Biobank, we found a weak positive phenotypic correlation between spouses for self-reported sleep duration (r = 0.11; 95% CI = 0.10, 0.12) and a weak inverse correlation for chronotype (diurnal preference) (r = -0.11; -0.12, -0.10), which replicated in up to 127,035 23andMe spouse-pairs. Using accelerometer data on 3454 UK Biobank spouse-pairs, the correlation for derived sleep duration was similar to self-report (r = 0.12; 0.09, 0.15). Timing of diurnal activity was positively correlated (r = 0.24; 0.21, 0.27) in contrast to the inverse correlation for chronotype. In Mendelian randomization analysis, positive effects of sleep duration (mean difference=0.13; 0.04, 0.23 SD per SD) and diurnal activity (0.49; 0.03, 0.94) were observed, as were inverse effects of chronotype (-0.15; -0.26, -0.04) and snoring (-0.15; -0.27, -0.04). Findings support the notion that an individual's sleep may impact that of their partner, promoting opportunities for sleep interventions at the family-level.

Evidence of correlations between human partners based on systematic reviews and meta-analyses of 22 traits and UK Biobank analysis of 133 traits

Positive correlations between mates can increase trait variation and prevalence, as well as bias estimates from genetically informed study designs. While past studies of similarity between human mating partners have largely found evidence of positive correlations, to our knowledge, no formal meta-analysis has examined human partner correlations across multiple categories of traits. Thus, we conducted systematic reviews and random-effects meta-analyses of human male-female partner correlations across 22 traits commonly studied by psychologists, economists, sociologists, anthropologists, epidemiologists and geneticists. Using ScienceDirect, PubMed and Google Scholar, we incorporated 480 partner correlations from 199 peer-reviewed studies of co-parents, engaged pairs, married pairs and/or cohabitating pairs that were published on or before 16 August 2022. We also calculated 133 trait correlations using up to 79,074 male-female couples in the UK Biobank (UKB). Estimates of the 22 mean meta-analysed correlations ranged from rmeta = 0.08 (adjusted 95% CI = 0.03, 0.13) for extraversion to rmeta = 0.58 (adjusted 95% CI = 0.50, 0.64) for political values, with funnel plots showing little evidence of publication bias across traits. The 133 UKB correlations ranged from rUKB = -0.18 (adjusted 95% CI = -0.20, -0.16) for chronotype (being a 'morning' or 'evening' person) to rUKB = 0.87 (adjusted 95% CI = 0.86, 0.87) for birth year. Across analyses, political and religious attitudes, educational attainment and some substance use traits showed the highest correlations, while psychological (that is, psychiatric/personality) and anthropometric traits generally yielded lower but positive correlations. We observed high levels of between-sample heterogeneity for most meta-analysed traits, probably because of both systematic differences between samples and true differences in partner correlations across populations.

Assortative mating and parental genetic relatedness drive the pathogenicity of variably expressive variants

We examined more than 38,000 spouse pairs from four neurodevelopmental disease cohorts and the UK Biobank to identify phenotypic and genetic patterns in parents associated with neurodevelopmental disease risk in children. We identified correlations between six phenotypes in parents and children, including correlations of clinical diagnoses such as obsessive-compulsive disorder (R=0.31-0.49, p<0.001), and two measures of sub-clinical autism features in parents affecting several autism severity measures in children, such as bi-parental mean Social Responsiveness Scale (SRS) scores affecting proband SRS scores (regression coefficient=0.11, p=0.003). We further describe patterns of phenotypic and genetic similarity between spouses, where spouses show both within- and cross-disorder correlations for seven neurological and psychiatric phenotypes, including a within-disorder correlation for depression (R=0.25-0.72, p<0.001) and a cross-disorder correlation between schizophrenia and personality disorder (R=0.20-0.57, p<0.001). Further, these spouses with similar phenotypes were significantly correlated for rare variant burden (R=0.07-0.57, p<0.0001). We propose that assortative mating on these features may drive the increases in genetic risk over generations and the appearance of "genetic anticipation" associated with many variably expressive variants. We further identified parental relatedness as a risk factor for neurodevelopmental disorders through its inverse correlations with burden and pathogenicity of rare variants and propose that parental relatedness drives disease risk by increasing genome-wide homozygosity in children (R=0.09-0.30, p<0.001). Our results highlight the utility of assessing parent phenotypes and genotypes in predicting features in children carrying variably expressive variants and counseling families carrying these variants.

Hazardous drinking and alcohol use disorders

Alcohol is one of the most widely consumed psychoactive drugs globally. Hazardous drinking, defined by quantity and frequency of consumption, is associated with acute and chronic morbidity. Alcohol use disorders (AUDs) are psychiatric syndromes characterized by impaired control over drinking and other symptoms. Contemporary aetiological perspectives on AUDs apply a biopsychosocial framework that emphasizes the interplay of genetics, neurobiology, psychology, and an individual's social and societal context. There is strong evidence that AUDs are genetically influenced, but with a complex polygenic architecture. Likewise, there is robust evidence for environmental influences, such as adverse childhood exposures and maladaptive developmental trajectories. Well-established biological and psychological determinants of AUDs include neuroadaptive changes following persistent use, differences in brain structure and function, and motivational determinants including overvaluation of alcohol reinforcement, acute effects of environmental triggers and stress, elevations in multiple facets of impulsivity, and lack of alternative reinforcers. Social factors include bidirectional roles of social networks and sociocultural influences, such as public health control strategies and social determinants of health. An array of evidence-based approaches for reducing alcohol harms are available, including screening, pharmacotherapies, psychological interventions and policy strategies, but are substantially underused. Priorities for the field include translating advances in basic biobehavioural research into novel clinical applications and, in turn, promoting widespread implementation of evidence-based clinical approaches in practice and health-care systems.

Similarities in cardiometabolic risk factors among random male-female pairs: a large observational study in Japan

Background:

Previous observational studies have shown similarities in cardiometabolic risk factors between spouses. It is still possible that this result reflects the age similarity of spouses rather than environmental factors of spouses (e.g. cohabitation effect). To clarify the importance of mate cardiometabolic risk factors for similarity of environmental factors, it is necessary to examine whether they are observed in random male-female pairs while maintaining the age of the spousal pairs. This study aimed to determine whether the similarities found between spousal pairs for cardiometabolic risks were also observed between random male-female pairs.

Methods:

This cross-sectional study included 5,391 spouse pairs from Japan; data were obtained from a large biobank study. For pairings, women of the same age were randomly shuffled to create new male-female pairs of the same age as that of the original spouse pairs. Similarities in cardiometabolic risk factors between the random male-female pairs were analysed using Pearson’s correlation or age-adjusted logistic regression analyses.

Results:

The mean ages of the men and women were 63.2 and 60.4 years, respectively. Almost all cardiometabolic risk factors similarities were not noted in cardiometabolic risk factors, including the continuous risk factors (anthropometric traits, blood pressure, glycated haemoglobin level, and lipid traits); lifestyle habits (smoking, drinking, and physical activity); or diseases (hypertension, type 2 diabetes mellitus, and metabolic syndrome) between the random male-female pairs. The age-adjusted correlation coefficients ranged from − 0.007 for body mass index to 0.071 for total cholesterol. The age-adjusted odds ratio (95% confidence interval) for current drinkers was 0.94 (0.81 − 1.09); hypertension, 1.07 (0.93 − 1.23); and type 2 diabetes mellitus, 1.08 (0.77 − 1.50).

Conclusion:

In this study, few similarities in cardiometabolic risk factors were noted among the random male-female pairs. As spouse pairs may share environmental factors, intervention strategies targeting lifestyle habits and preventing lifestyle-related diseases may be effective.

Spousal Concordance and Cross-Disorder Concordance of Mental Disorders: A Nationwide Cohort Study

OBJECTIVE

Although both partners of a married couple can have mental disorders, the concordant and cross-concordant categories of disorders in couples remain unclear. Using national psychiatric population-based data only from patients with mental disorders, we examined married couples with mental disorders to examine spousal concordance and cross-disorder concordance across the full spectrum of mental disorders.

METHODS

Data from the 1997 to 2012 Taiwan Psychiatric Inpatient Medical Claims data set were used and a total of 662 married couples were obtained. Concordance of mental disorders was determined if both spouses were diagnosed with mental disorder of an identical category in the International Classification of Diseases, Ninth Revision, Clinical Modification; otherwise, cross-concordance was reported.

RESULTS

According to Cohen's kappa coefficient, the most concordant mental disorder in couples was substance use disorder, followed by bipolar disorder. Depressive and anxiety disorders were the most common cross-concordant mental disorders, followed by bipolar disorder. The prevalence of the spousal concordance of mental disorders differed by monthly income and the couple's age disparity.

CONCLUSION

Evidence of spousal concordance and cross-concordance for mental disorders may highlight the necessity of understanding the social context of marriage in the etiology of mental illness. Identifying the risk factors from a common environment attributable to mental disorders may enhance public health strategies to prevent and improve chronic mental illness of married couples.

Prenatal smoking, alcohol and caffeine exposure and maternal-reported attention deficit hyperactivity disorder symptoms in childhood: triangulation of evidence using negative control and polygenic risk score analyses

BACKGROUND AND AIMS

Studies have indicated that maternal prenatal substance use may be associated with offspring attention deficit hyperactivity disorder (ADHD) via intrauterine effects. We measured associations between prenatal smoking, alcohol and caffeine consumption with childhood ADHD symptoms accounting for shared familial factors.

DESIGN

First, we used a negative control design comparing maternal and paternal substance use. Three models were used for negative control analyses: unadjusted (without confounders), adjusted (including confounders) and mutually adjusted (including confounders and partner's substance use). The results were meta-analysed across the cohorts. Secondly, we used polygenic risk scores (PRS) as proxies for exposures. Maternal PRS for smoking, alcohol and coffee consumption were regressed against ADHD symptoms. We triangulated the results across the two approaches to infer causality.

SETTING

We used data from three longitudinal pregnancy cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC) in the United Kingdom, Generation R study (GenR) in the Netherlands and Norwegian Mother, Father and Child Cohort study (MoBa) in Norway.

PARTICIPANTS

Phenotype data available for children were: NALSPAC  = 5455-7751; NGENR  = 1537-3119; NMOBA  = 28 053-42 206. Genotype data available for mothers was: NALSPAC  = 7074; NMOBA  = 14 583.

MEASUREMENTS

A measure of offspring ADHD symptoms at age 7-8 years was derived by dichotomizing scores from questionnaires and parental self-reported prenatal substance use was measured at the second pregnancy trimester.

FINDINGS

The pooled estimate for maternal prenatal substance use showed an association with total ADHD symptoms [odds ratio (OR)SMOKING  = 1.11, 95% confidence interval (CI) = 1.00-1.23; ORALCOHOL  = 1.27, 95% CI = 1.08-1.49; ORCAFFEINE  = 1.05, 95% CI = 1.00-1.11], while not for fathers (ORSMOKING  = 1.03, 95% CI = 0.95-1.13; ORALCOHOL  = 0.83, 95% CI = 0.47-1.48; ORCAFFEINE  = 1.02, 95% CI = 0.97-1.07). However, maternal associations did not persist in sensitivity analyses (substance use before pregnancy, adjustment for maternal ADHD symptoms in MoBa). The PRS analyses were inconclusive for an association in ALSPAC or MoBa.

CONCLUSIONS

There appears to be no causal intrauterine effect of maternal prenatal substance use on offspring attention deficit hyperactivity disorder symptoms.

Indirect Genetic Effects: A Cross-disciplinary Perspective on Empirical Studies

Indirect genetic effects (IGE) occur when an individual's phenotype is influenced by genetic variation in conspecifics. Opportunities for IGE are ubiquitous, and, when present, IGE have profound implications for behavioral, evolutionary, agricultural, and biomedical genetics. Despite their importance, the empirical study of IGE lags behind the development of theory. In large part, this lag can be attributed to the fact that measuring IGE, and deconvoluting them from the direct genetic effects of an individual's own genotype, is subject to many potential pitfalls. In this Perspective, we describe current challenges that empiricists across all disciplines will encounter in measuring and understanding IGE. Using ideas and examples spanning evolutionary, agricultural, and biomedical genetics, we also describe potential solutions to these challenges, focusing on opportunities provided by recent advances in genomic, monitoring, and phenotyping technologies. We hope that this cross-disciplinary assessment will advance the goal of understanding the pervasive effects of conspecific interactions in biology.

Effect of long-acting injectable antipsychotics on hospitalizations and global functioning in schizophrenia: a naturalistic mirror-image study

BACKGROUND

Partial adherence to antipsychotics is the most common cause of relapses and rehospitalization in patients with schizophrenia (SZ), leading to higher health care costs and psychosocial disability. The use of long-acting injectable (LAI) antipsychotics may improve therapeutic continuity and adherence to treatment.

OBJECTIVE

To assess the effectiveness of switching from oral antipsychotics (OAs) to long-acting antipsychotics.

METHODS

This 1-year mirror-image study evaluated the effect of switching from OAs to LAIs on the reduction of psychiatric hospitalizations and the improvement of global functioning in patients with schizophrenia. Differences in outcomes between second-generation (SGA) LAIs and first-generation (FGA) LAIs were also analyzed.

RESULTS

In all, 166 patients were included: 32.5% treated by FGA-LAIs and 67.5% by SGA-LAIs. There was an overall reduction of 71% in the average number of hospital admissions and an overall improvement of 29.3% in the Global Assessment of Functioning (GAF) score between the previous 12 months and the 12 months following the switching to LAIs. Patients who switched to SGA-LAIs had no significant differences in hospitalization occurrences but a significant improvement in GAF scores when compared with patients who switched to FGA-LAIs.

CONCLUSION

Our results suggest that using LAIs could be the most adequate treatment choice for SZ patients with a high risk of relapse and low adherence rate. Patients with poorer social functioning may be ideal candidates for SGA-LAIs treatment. Our findings may be of particular interest from a clinical and health care management perspective.

Spousal associations of serum metabolomic profiles by nuclear magnetic resonance spectroscopy

Phenotype-based assortative mating is well established in humans, with the potential for further convergence through a shared environment. To assess the correlation within infertile couples of physical, social, and behavioural characteristics and 155 circulating metabolic measures. Cross sectional study at a tertiary medical center of 326 couples undertaking IVF. Serum lipids, lipoprotein subclasses, and low-molecular weight metabolites as quantified by NMR spectroscopy (155 metabolic measures). Multivariable and quantile regression correlations within couples of metabolite profiles. Couples exhibited statistical correlations of varying strength for most physical, social, and behavioural characteristics including age, height, alcohol consumption, education, smoking status, physical activity, family history and ethnicity, with correlation coefficients ranging from 0.22 to 0.73. There was no evidence of within couple associations for BMI and weight, where the correlation coefficients were - 0.03 (95% CI - 0.14, 0.08) and 0.01 (95% CI - 0.10, 0.12), respectively. Within spousal associations of the metabolite measurements were all positive but with weak to modest magnitudes, with the median correlation coefficient across all 155 measures being 0.12 (range 0.01-0.37 and interquartile range 0.10-0.18). With just four having associations stronger than 0.3: docosahexaenoic acid (0.37, 95% CI 0.22, 0.52), omega-3 fatty acids (0.32, 95% CI 0.20, 0.43) histidine (0.32, 95% CI 0.23, 0.41) and pyruvate (0.32, 95% CI 0.22, 0.43). Infertile couples exhibit spousal similarities for a range of demographic and serum metabolite measures, supporting initial assortative mating, with diet-derived metabolites suggesting possible subsequent convergence of their individual metabolic profile.

Spousal similarities in cardiometabolic risk factors: A cross-sectional comparison between Dutch and Japanese data from two large biobank studies

BACKGROUND AND AIMS

Few studies have examined and compared spousal concordance in different populations. This study aimed to quantify and compare spousal similarities in cardiometabolic risk factors and diseases between Dutch and Japanese populations.

METHODS

This cross-sectional study included 28,265 Dutch Lifelines Cohort Study spouse pairs (2006-2013) and 5,391 Japanese Tohoku Medical Megabank Organization (ToMMo) Cohort Study pairs (2013-2016). Spousal similarities in cardiometabolic risk factors were evaluated using Pearson's correlation or logistic regression analyses adjusted for spousal age.

RESULTS

The husbands' and wives' average ages in the Lifelines and ToMMo cohorts were 50.0 and 47.7 years and 63.2 and 60.4 years, respectively. Significant spousal similarities occurred with all cardiometabolic risk factors and diseases of interest in both cohorts. The age-adjusted correlation coefficients ranged from 0.032 to 0.263, with the strongest correlations observed in anthropometric traits. Spousal odds ratios [95% confidence interval] for the Lifelines vs. ToMMo cohort ranged from 1.45 (1.36-1.55) vs. 1.20 (1.05-1.38) for hypertension to 6.86 (6.30-7.48) vs. 4.60 (3.52-6.02) for current smoking. An increasing trend in spousal concordance with age was observed for sufficient physical activity in both cohorts. For current smoking, those aged 20-39 years showed the strongest concordance between pairs in both cohorts. The Dutch pairs showed stronger similarities in anthropometric traits and lifestyle habits (smoking and drinking) than their Japanese counterparts.

CONCLUSIONS

Spouses showed similarities in several cardiometabolic risk factors among Dutch and Japanese populations, with regional and cultural influences on spousal similarities.

Genetic and shared couple environmental contributions to smoking and alcohol use in the UK population

Alcohol use and smoking are leading causes of death and disability worldwide. Both genetic and environmental factors have been shown to influence individual differences in the use of these substances. In the present study we tested whether genetic factors, modelled alongside common family environment, explained phenotypic variance in alcohol use and smoking behaviour in the Generation Scotland (GS) family sample of up to 19,377 individuals. SNP and pedigree-associated effects combined explained between 18 and 41% of the variance in substance use. Shared couple effects explained a significant amount of variance across all substance use traits, particularly alcohol intake, for which 38% of the phenotypic variance was explained. We tested whether the within-couple substance use associations were due to assortative mating by testing the association between partner polygenic risk scores in 34,987 couple pairs from the UK Biobank (UKB). No significant association between partner polygenic risk scores were observed. Associations between an individual's alcohol PRS (b = 0.05, S.E. = 0.006, p < 2 × 10-16) and smoking status PRS (b = 0.05, S.E. = 0.005, p < 2 × 10-16) were found with their partner's phenotype. In support of this, G carriers of a functional ADH1B polymorphism (rs1229984), known to be associated with greater alcohol intake, were found to consume less alcohol if they had a partner who carried an A allele at this SNP. Together these results show that the shared couple environment contributes significantly to patterns of substance use. It is unclear whether this is due to shared environmental factors, assortative mating, or indirect genetic effects. Future studies would benefit from longitudinal data and larger sample sizes to assess this further.

Using a developmental perspective to examine the moderating effects of marriage on heavy episodic drinking in a young adult sample enriched for risk

Many studies demonstrate that marriage protects against risky alcohol use and moderates genetic influences on alcohol outcomes; however, previous work has not considered these effects from a developmental perspective or in high-risk individuals. These represent important gaps, as it cannot be assumed that marriage has uniform effects across development or in high-risk samples. We took a longitudinal developmental approach to examine whether marital status was associated with heavy episodic drinking (HED), and whether marital status moderated polygenic influences on HED. Our sample included 937 individuals (53.25% female) from the Collaborative Study on the Genetics of Alcoholism who reported their HED and marital status biennially between the ages of 21 and 25. Polygenic risk scores (PRS) were derived from a genome-wide association study of alcohol consumption. Marital status was not associated with HED; however, we observed pathogenic gene-by-environment effects that changed across young adulthood. Among those who married young (age 21), individuals with higher PRS reported more HED; however, these effects decayed over time. The same pattern was found in supplementary analyses using parental history of alcohol use disorder as the index of genetic liability. Our findings indicate that early marriage may exacerbate risk for those with higher polygenic load.

Pharmacotherapies for the Treatment of Alcohol Use Disorders During Pregnancy: Time to Reconsider?

It is generally recommended that medications only be used in pregnancy where the potential harms to both the mother and foetus are outweighed by the potential benefits. Despite the known harms associated with alcohol consumption during pregnancy, the use of medication for the treatment of pregnant women with an alcohol use disorder (AUD) appears to be rare. This is likely due to the lack of available data regarding the safety of these medications in pregnancy. We reviewed the literature and weighed up the harms associated with alcohol use and AUD during pregnancy with the potential benefits of medications for AUD in pregnancy, including acamprosate, naltrexone and disulfiram. There is little published evidence to support the safety of medications for AUD in pregnancy. However, from the research available it is likely that only disulfiram has the potential to cause serious foetal harm. While further research is required, acamprosate and naltrexone do not appear to be associated with substantial risks of congenital malformations or other serious consequences. Given the potential risks associated with alcohol consumption during pregnancy, the use of acamprosate and naltrexone should be considered for the treatment of pregnant women with AUD based on the current evidence base, although more research is warranted.

Quantile-Specific Heritability of Intakes of Alcohol but not Other Macronutrients

Genetic heritability (h2) of alcohol use is reported to be greater in rural dwellers, distressed marriages, low socioeconomic status, in girls who are unmarried or lacking closeness with their parents or religious upbringing, in less-educated men, and in adolescents with peers using alcohol. However, these are all risk factors for heavy drinking, and the greater heritability could be due to quantile-dependent expressivity, i.e., h2 dependent upon whether the phenotype (alcohol intake) is high or low relative to its distribution. Quantile regression showed that h2 estimated from the offspring-parent regression slope increased significantly from lowest to highest gram/day of alcohol consumption (0.006 ± 0.001 per percent, P = 1.1 × 10-7). Heritability at the 90th percentile of the sample distribution (0.557 ± 0.116) was 4.5-fold greater than at the 10th percentile (0.122 ± 0.037). Heritabilities for intakes of other macronutrients were not quantile-dependent. Thus quantile-dependent expressivity may explain the higher estimated heritability associated with risk factors for high alcohol consumption.

Evaluating the Impact of Nonrandom Mating: Psychiatric Outcomes Among the Offspring of Pairs Diagnosed With Schizophrenia and Bipolar Disorder

BACKGROUND

Nonrandom mating has been shown for psychiatric diagnoses, with hypothesized-but not quantified-implications for offspring liability. This national cohort study enumerated the incidence of major psychiatric disorders among the offspring of parent pairs affected with schizophrenia (SCZ) and/or bipolar disorder (BIP) (i.e., dual-affected pairs).

METHODS

Participants were all Swedish residents alive or born between 1968 and 2013 (n = 4,255,196 unique pairs and 8,343,951 offspring). Offspring with dual-affected, single-affected, and unaffected parents were followed (1973-2013) for incidence of broad psychiatric disorders. Primary outcomes included hazard ratio (HR) and cumulative incidence for SCZ and BIP in the offspring. Additional outcomes included any neuropsychiatric, anxiety, depressive, personality, or substance use disorders. Cumulative incidences of SCZ and BIP were used to inform heritability models for these disorders.

RESULTS

Hazards were highest within disorder (e.g., offspring of dual-SCZ pairs had sharply raised hazards for SCZ [HR = 55.3]); however, they were significantly raised for all diagnoses (HR range = 2.89-11.84). Incidences were significantly higher for the majority of outcomes, with 43.4% to 48.5% diagnosed with "any" disorder over follow-up. Risks were retained, with modest attenuations, for the offspring of heterotypic pairs. The estimated heritability of liability for SCZ (h2 = 0.62, 95% confidence interval = 0.55-0.70) and BIP (h2 = 0.52, 95% confidence interval = 0.46-0.58) did not differ significantly from estimates derived from single-affected parents.

CONCLUSIONS

Risks for a broad spectrum of psychiatric diagnoses are significantly raised in the offspring of dual-affected parents, in line with expectations from a polygenic model of liability to disease risk. How these risks may contribute to population maintenance of these disorders is considered.

Genetic evidence for assortative mating on alcohol consumption in the UK Biobank

Alcohol use is correlated within spouse-pairs, but it is difficult to disentangle effects of alcohol consumption on mate-selection from social factors or the shared spousal environment. We hypothesised that genetic variants related to alcohol consumption may, via their effect on alcohol behaviour, influence mate selection. Here, we find strong evidence that an individual's self-reported alcohol consumption and their genotype at rs1229984, a missense variant in ADH1B, are associated with their partner's self-reported alcohol use. Applying Mendelian randomization, we estimate that a unit increase in an individual's weekly alcohol consumption increases partner's alcohol consumption by 0.26 units (95% C.I. 0.15, 0.38; P = 8.20 × 10-6). Furthermore, we find evidence of spousal genotypic concordance for rs1229984, suggesting that spousal concordance for alcohol consumption existed prior to cohabitation. Although the SNP is strongly associated with ancestry, our results suggest some concordance independent of population stratification. Our findings suggest that alcohol behaviour directly influences mate selection.

Simulations and directed acyclic graphs explained why assortative mating biases the prenatal negative control design

OBJECTIVE

The negative control design can be used to provide evidence for whether a prenatal exposure-outcome association occurs by in utero mechanisms. Assortative mating has been suggested to influence results from negative control designs, although how and why has not yet been adequately explained. We aimed to explain why mutual adjustment of maternal and paternal exposure in regression models can account for assortative mating.

STUDY DESIGN AND SETTING

We used directed acyclic graphs to show how bias can occur when modeling maternal and paternal effects separately. We empirically tested our claims using a simulation study. We investigated how increasing assortative mating influences the bias of effect estimates obtained from models that do and do not use a mutual adjustment strategy.

RESULTS

In models without mutual adjustment, increasing assortative mating led to increased bias in effect estimates. The maternal and paternal effect estimates were biased by each other, making the difference between them smaller than the true difference. Mutually adjusted models did not suffer from such bias.

CONCLUSIONS

Mutual adjustment for maternal and paternal exposure prevents bias from assortative mating influencing the conclusions of a negative control design. We further discuss issues that mutual adjustment may not be able to resolve.

Why spouses depress each other: A cross-national study to test the shared resource hypothesis in depressive symptom concordance within older adult couples

The shared resource hypothesis suggests that married couples share the same environmental resources, which shape their health concordance. This study tests its cross-national applicability. Cross-sectional 2012-2013 Health and Retirement Study data from China, England, Mexico, and the United States were analyzed. Heterosexual couples (age ≥60) who were married or partnered were studied (N = 20,565 pairs). Dyadic data were analyzed by multilevel models to examine the effect of self and spousal social and physical health statuses on depressive symptoms. Regression models were used to test the relationship between couples' shared resources and depressive symptom concordance. Results indicated both husbands and wives' depressive symptoms were associated with their own and spouses' social and health statuses. Most couple-level resources were insignificant predictors for Chinese and Mexican couples' concordance, but having more social and financial resources was associated with higher concordance among British and American couples. Self-reported health was the most consistent predictor in all countries. The shared resource hypothesis was more applicable to depressive symptom concordance within couples in the United States and England, but not in China and Mexico. Couple-centered intervention is suggested for clinical practice, and the spousal effect should be considered in policymaking.

Intelligence in young adulthood and alcohol use disorders in a prospective cohort study of Danish men: the role of psychiatric disorders and parental psychiatric history

OBJECTIVES

The aims were to estimate the association between intelligence measured in young adulthood and risk of alcohol use disorders (AUD) in men and to investigate the potential modification of this association by psychiatric disorders, parental AUD and parental psychiatric disorders.

DESIGN

Prospective cohort study based on a linkage of intelligence test scores from draft board examinations and register data on AUD diagnoses during 36 years of follow-up.

SETTING

Denmark.

PARTICIPANTS

3287 Danish men from the Copenhagen Perinatal Cohort (born 1959-1961) who appeared before the draft board at a mean age of 18.7 years.

PRIMARY OUTCOME MEASURE

First registration with AUD during follow-up was the primary outcome. Information on AUD was based on diagnoses retrieved from national hospital and outpatient treatment registers, defined according to the International Classification of Diseases.

RESULTS

361 (11.0%) men were registered with AUD during follow-up. Low intelligence scores were associated with increased odds of AUD adjusting for parental AUD, parental psychiatric disorders, maternal smoking during pregnancy, birth weight, maternal age at birth, parity and childhood socioeconomic position (OR per SD decrease in intelligence=1.69, 95% CI 1.49 to 1.92). Separate analyses indicated significant interaction (p<0.001) between intelligence and psychiatric disorders. The adjusted OR per SD decrease in intelligence score was 2.04 (95% CI 1.67 to 2.49) in men without other psychiatric disorders whereas the OR was 1.21 (95% CI 1.01 to 1.46) in men with other psychiatric disorders. No interaction was found between intelligence and parental AUD or between intelligence and parental psychiatric disorders.

CONCLUSIONS

The association between intelligence in young adulthood and AUD is modified by other psychiatric disorders as low intelligence is primarily a risk factor for men without other psychiatric disorders. Future studies should take other psychiatric disorders into account when investigating associations between intelligence and AUD.

The etiology of DSM-5 alcohol use disorder: Evidence of shared and non-shared additive genetic effects

BACKGROUND

Alcoholism is a multifactorial disorder influenced by multiple gene loci, each with small effect. Studies suggest shared genetic influences across DSM-IV alcohol dependence symptoms, but shared effects across DSM-5 alcohol use disorder remains unknown. We aimed to test the assumption of genetic homogeneity across the 11 criteria of DSM-5 alcohol use disorder (AUD).

METHODS

Data from 2596 alcohol using individuals of European ancestry from the Study of Addiction: Genetics and Environment were used to examine the genomewide SNP-heritability (h2SNP) and SNP-covariance (rGSNP) between 11 DSM-5 AUD symptoms. Phenotypic relationships between symptoms were examined to confirm an underlying liability of AUD and the SNP-heritability of the observed latent trait and the co-heritabilityamong AUD symptoms was assessed using Genomic-Relatedness-Matrix-Restricted-Maximum-Likelihood. Genetic covariance among symptoms was examined using factor analysis.

RESULTS

Phenotypic relationships confirmed a unidimensional underlying liability to AUD. Factor and parallel analyses of the observed genetic variance/covariance provided evidence of genetic homogeneity. Additive genetic effects on DSM-5 AUD symptoms varied from 0.10 to 0.37 and largely overlapped (rG-SNP across symptoms ranged from 0.49 - 0.92). The additive genetic effect on the DSM-5 AUD factor was 0.36, 0.14 for DSM-5 AUD diagnosis, and was 0.22 for DSM-5 AUD severity.

CONCLUSIONS

Common genetic variants influence DSM-5 AUD symptoms. Despite evidence for a common AUD factor, the evidence of only partially overlapping genetic effects across AUD symptoms further substantiates the need to simultaneously model common and symptom-specific genetic effects in molecular genetic studies in order to best characterize the genetic liability.

In utero exposure to selective serotonin reuptake inhibitors and development of mental disorders: a systematic review and meta-analysis

OBJECTIVE

Several studies have investigated whether in utero exposure to selective serotonin reuptake inhibitors (SSRIs) is associated with increased risk of developing mental or behavioural disorders. The aim of this study was to perform a systematic review and meta-analysis based on this literature.

METHODS

A systematic search of eligible literature in PubMed, EMBASE, and PsycINFO and subsequent meta-analysis was conducted in adherence with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline.

RESULTS

A total of 20 studies were included in the review, and results from 18 of these were meta-analyzed. We found a statistically significant positive association between in utero exposure to SSRIs and mental or behavioural disorders such as autism spectrum disorder (hazard ratio (HR) = 1.27; 95% confidence interval (CI) = 1.10-1.47), attention-deficit/hyperactivity disorder (HR = 1.33; 95% CI = 1.06-1.66) and mental retardation (HR = 1.41; 95% CI = 1.03-1.91). Confounding by indication was identified in five of seven studies investigating this aspect.

CONCLUSION

Exposure to SSRIs in utero is associated with increased risk of developing mental or behavioural disorders. However, these associations do not necessarily reflect a causal relationship since the results included in this meta-analysis are likely affected by residual confounding by indication, which is likely to account for some (or all) of the positive association.

Out Drinking the Joneses: Neighborhood Factors Moderating the Effects of Drinking on Relationship Quality over the First Four Years of Marriage

Neighborhood quality has been cross-sectionally linked to both relationship behaviors and relationship well-being. Consistent with the Vulnerability Stress-Adaptation model of relationship functioning (Karney & Bradbury, 1995), we hypothesized that associations between social behaviors (e.g., drinking) and relationship quality could be moderated by neighborhood factors. Specifically, we characterized neighborhoods along multiple dimensions using multiple methods (self-report, census) to investigate how neighborhood factors might clarify ambiguous effects of alcohol use on marital functioning. A nationally recruited sample of 303 newlywed couples completed a baseline assessment around the time of marriage and was then assessed yearly across the first 4 years of marriage (94% retention). Three level HLM slope-intercept models were used to model changes in relationship satisfaction across the first 4 years of marriage. Results suggested that, for couples living in highly disordered neighborhoods, positive shifts in overall levels of drinking within specific waves of assessment were associated with corresponding negative shifts in satisfaction whereas in neighborhoods without perceived disorder, this effect was reversed. For couples living in neighborhoods with low levels of domestic structures (high census rates of single renters without children), within-couple discrepancies favoring higher rates of husband drinking in specific waves predicted poorer relationship quality for both partners in those same waves whereas those same discrepancies predicted higher satisfaction in high domesticity neighborhoods (high census rates of married homeowners with children). The findings provide insight into the different roles of alcohol use in relationship maintenance and highlight the importance of using external context to understand intradyadic processes.

Hazardous alcohol consumption among spouses or partners of military service personnel: a systematic review of the literature

BACKGROUND

Alcohol misuse is particularly high among both the UK and US Armed Forces. As alcohol use among couples is associated, military spouses or partners may therefore be at a higher risk of acquiring hazardous drinking behaviours than people in relationships with other occupational groups.

METHOD

A literature review using a systematic approach was undertaken in four medical databases and supplemented with hand searches of specialist publications and reference lists. The prevalence of hazardous alcohol consumption among military spouses or partners was estimated and potential sociodemographic and military factors associated with this outcome were identified.

RESULTS

Nine papers met inclusion criteria, of which eight focused on female spouses or partners only. The limited evidence suggests hazardous alcohol consumption was not a common outcome among spouses or partners. None of the papers statistically compared the prevalence among spouses or partners to estimates from the general population and few reported associations with sociodemographic or military factors. Deployment abroad did not appear to be significantly associated with hazardous consumption, although increasing periods of separation from Service personnel may be associated with increased hazardous consumption among spouses or partners.

CONCLUSION

Limited evidence was found concerning the prevalence of hazardous alcohol consumption among military spouses or partners or which sociodemographic and military factors might be associated with this outcome. The a dominance of US studies means applying the estimates of these outcomes to other nations must be undertaken with care due to differences in cultural attitudes to alcohol as well as differences between military structure and operations between the US and other nations.

Social network perspective on alcohol consumption among African American women: a longitudinal analysis

OBJECTIVE

The aim of the study was to examine alcohol use in African American women's social networks.

DESIGN

This was a longitudinal study of African American women and their social networks in Baltimore, MD. Data were collected through face-to-face interviews at a community-based research clinic. Alcohol consumption frequency was assessed by a single question 'How often do you drink alcohol?' with a four-point ordinal rating scale 'never,' 'monthly or less,' '2-4 times a month' and '>2 times a week.' A longitudinal ordinal logistic model was conducted to use 317 African American women's alcohol consumption frequency as a predictor of their social networks' alcohol consumption frequency.

RESULTS

Results show that African American women's alcohol consumption frequency was a statistically significant predictor of their social network members' alcohol consumption frequency.

CONCLUSION

Findings suggest the merit of social network-based approaches to address alcohol use among urban minority populations.

Sources of Parent-Child Transmission of Drug Abuse: Path Analyses of Not-Lived-With Parental, Stepparental, Triparental, and Adoptive Families

To clarify the origins of parent-child resemblance for drug abuse (DA), using national Swedish data, we fit path models to information on DA in parents and children from six informative family types: i) not-lived-with father, ii) not-lived-with mother, iii) stepfather, iv) stepmother, v) triparental, and vi) adoptive. From these families, we estimated parent-offspring resemblance reflecting the effects of genes + rearing, genes only, and rearing only. The estimates of parent-offspring correlations were statistically homogenous across family types. The weighted estimate of the father-offspring correlation for DA for genes + rearing, genes-only, and rearing-only relationships were, respectively, +0.26, +0.19, and +0.06. Parallel figures for mother-offspring relationships were +0.19, +0.13, and +0.09. In both genes + rearing and genes-only parent-offspring relationships, DA correlations were stronger for fathers than for mothers. Both genetic and environmental factors contribute substantially to parent-offspring resemblance for DA and seem to be additive.

The Origin of Spousal Resemblance for Alcohol Use Disorder

IMPORTANCE

Although spouses strongly resemble one another in their risk for alcohol use disorder (AUD), the causes of this association remain unclear.

OBJECTIVES

To examine longitudinally, in first marriages, the association of a first registration for AUD in one spouse with risk of registration in his or her partner and to explore changes in the risk for AUD registration in individuals with multiple marriages as they transition from a spouse with AUD to one without or vice versa.

DESIGN, SETTING, AND PARTICIPANTS

Population-wide Swedish registries were used to identify individuals born in Sweden between 1960 and 1990 who were married before the end of study follow-up on December 31, 2013. The study included 8562 marital pairs with no history of AUD registration prior to their first marriage and an AUD registration in 1 spouse during marriage and 4891 individuals with multiple marriages whose first spouse had no AUD registration and second spouse did or vice versa. Final statistical analyses were conducted from August 15 to September 1, 2017.

EXPOSURES

A spousal onset or history of AUD registration.

MAIN OUTCOMES AND MEASURES

Alcohol use disorder registration in national medical, criminal, or pharmacy registries.

RESULTS

Among the 8562 marital pairs (5883 female probands and 2679 male probands; mean [SD] age at marriage, 29.2 [5.7] years) in first marriages, the hazard ratio of AUD registration in wives immediately after the first AUD registration in their husbands was 13.82, which decreased 2 years later to 3.75. The hazard ratio of AUD registration in husbands after the first AUD registration in their wives was 9.21, which decreased 2 years later to 3.09. Among the 4891 individuals with multiple marriages (1439 women and 3452 men; mean [SD] age at first marriage, 25.5 [4.2] years), when individuals transitioned from a first marriage to a spouse with AUD to a second marriage to a spouse without AUD, the hazard ratio for AUD registration was 0.50 (95% CI, 0.42-0.59) in women and 0.51 (95% CI, 0.44-0.59) in men. After a first marriage to a spouse without AUD, the hazard ratio for AUD with a second marriage to a spouse with AUD was 7.02 (95% CI, 5.34-9.23) in women and 9.06 (95% CI, 7.55-10.86) in men. These patterns were modestly attenuated when moving from second to third marriages. Controlling for AUD registration prior to first marriage or between first and second marriages produced minimal changes in risk.

CONCLUSIONS AND RELEVANCE

The increase in risk for AUD registration in a married individual following a first AUD registration in the spouse is large and rapid. When an individual with serial spouses is married, in either order, to partners with vs without an AUD registration, the risk for AUD registration is substantially increased when the partner has an AUD registration and decreased when the partner does not have an AUD registration. These results suggest that a married individual's risk for AUD is directly and causally affected by the presence of AUD in his or her spouse.

Fathers' Alcohol and Cannabis Use Disorder and Early Onset of Drug Use by Their Children

OBJECTIVE

The unique influence of fathers' alcohol and cannabis use disorder on children's onset of use of these same substances has been rarely studied. A clear understanding of family history in this context is important for the development of family-based prevention initiatives aimed at delaying the onset of substance use among children.

METHOD

Prospective, longitudinal, and intergenerational data on 274 father-child dyads were used. Logistic regression models were estimated to assess the association between fathers' lifetime incidence of an alcohol and cannabis use disorder and children's onset of use of these same substances at or before age 15.

RESULTS

The children of fathers who met the criteria for a lifetime cannabis use disorder were more likely to initiate use of alcohol (odds ratio = 6.71, 95% CI [1.92, 23.52]) and cannabis (odds ratio = 8.13, 95% CI [2.07, 31.95]) by age 15, when background covariates and presence of a lifetime alcohol use disorder were controlled for. No unique effect of fathers' alcohol use disorder on children's onset of alcohol and cannabis use was observed.

CONCLUSIONS

Fathers' lifetime cannabis use disorder had a unique and robust association with children's uptake of alcohol and cannabis by age 15. Future research is needed to identify the mediating mechanisms that link fathers' disorder with children's early onset.

Developmental Origins of Chronic Physical Aggression: A Bio-Psycho-Social Model for the Next Generation of Preventive Interventions

This review describes a bio-psycho-social approach to understanding and preventing the development of chronic physical aggression. The debate on the developmental origins of aggression has historically opposed genetic and environmental mechanisms. Recent studies have shown that the frequency of physical aggression peaks in early childhood and then decreases until old age. Molecular genetic studies and twin studies have confirmed important genetic influences. However, recent epigenetic studies have highlighted the important role of environments in gene expression and brain development. These studies suggest that interrelated bio-psycho-social channels involved in the development of chronic physical aggression are generally the product of an intergenerational transmission process occurring through assortative mating, genetic inheritance, and the inheritance of physical and social environmental conditions that handicap brain functioning and support the use of physical aggression to solve problems. Given these intergenerational mechanisms and physical aggression onset in infancy, it appears clear that preventive interventions should start early in pregnancy, at the latest.

Familial Resemblance in Dietary Intakes of Children, Adolescents, and Parents: Does Dietary Quality Play a Role?

Information on familial resemblance is important for the design of effective family-based interventions. We aimed to quantify familial correlations and estimate the proportion of variation attributable to genetic and shared environmental effects (i.e., familiality) for dietary intake variables and determine whether they vary by generation, sex, dietary quality, or by the age of the children. The study sample consisted of 1435 families (1007 mothers, 438 fathers, 1035 daughters, and 1080 sons) from the multi-center I.Family study. Dietary intake was assessed in parents and their 2–19 years old children using repeated 24-h dietary recalls, from which the usual energy and food intakes were estimated with the U.S. National Cancer Institute Method. Food items were categorized as healthy or unhealthy based on their sugar, fat, and fiber content. Interclass and intraclass correlations were calculated for relative pairs. Familiality was estimated using variance component methods. Parent–offspring (r = 0.11–0.33), sibling (r = 0.21–0.43), and spouse (r = 0.15–0.33) correlations were modest. Parent–offspring correlations were stronger for the intake of healthy (r = 0.33) than unhealthy (r = 0.10) foods. Familiality estimates were 61% (95% CI: 54–68%) for the intake of fruit and vegetables and the sum of healthy foods and only 30% (95% CI: 23–38%) for the sum of unhealthy foods. Familial factors explained a larger proportion of the variance in healthy food intake (71%; 95% CI: 62–81%) in younger children below the age of 11 than in older children equal or above the age of 11 (48%; 95% CI: 38–58%). Factors shared by family members such as genetics and/or the shared home environment play a stronger role in shaping children’s intake of healthy foods than unhealthy foods. This suggests that family-based interventions are likely to have greater effects when targeting healthy food choices and families with younger children, and that other sorts of intervention are needed to address the intake of unhealthy foods by children.

Investigating spousal concordance of diabetes through statistical analysis and data mining

OBJECTIVE

Spousal clustering of diabetes merits attention. Whether old-age vulnerability or a shared family environment determines the concordance of diabetes is also uncertain. This study investigated the spousal concordance of diabetes and compared the risk of diabetes concordance between couples and noncouples by using nationally representative data.

METHODS

A total of 22,572 individuals identified from the 2002-2013 National Health Insurance Research Database of Taiwan constituted 5,643 couples and 5,643 noncouples through 1:1 dual propensity score matching (PSM). Factors associated with concordance in both spouses with diabetes were analyzed at the individual level. The risk of diabetes concordance between couples and noncouples was compared at the couple level. Logistic regression was the main statistical method. Statistical data were analyzed using SAS 9.4. C&RT and Apriori of data mining conducted in IBM SPSS Modeler 13 served as a supplement to statistics.

RESULTS

High odds of the spousal concordance of diabetes were associated with old age, middle levels of urbanization, and high comorbidities (all P < 0.05). The dual PSM analysis revealed that the risk of diabetes concordance was significantly higher in couples (5.19%) than in noncouples (0.09%; OR = 61.743, P < 0.0001).

CONCLUSIONS

A high concordance rate of diabetes in couples may indicate the influences of assortative mating and shared environment. Diabetes in a spouse implicates its risk in the partner. Family-based diabetes care that emphasizes the screening of couples at risk of diabetes by using the identified risk factors is suggested in prospective clinical practice interventions.

Volunteering and mortality risk: a partner-controlled quasi-experimental design

Background

The consensus that volunteering is associated with a lower mortality risk is derived from a body of observational studies and therefore vulnerable to uncontrolled or residual confounding. This potential limitation is likely to be particularly problematic for volunteers who, by definition, are self-selected and known to be significantly different from non-volunteers across a range of factors associated with better survival.

Methods

This is a census-based record-linkage study of 308 733 married couples aged 25 and over, including 100 571 volunteers, with mortality follow-up for 33 months. We used a standard Cox model to examine whether mortality risk in the partners of volunteers was influenced by partner volunteering status-something expected if the effects of volunteering on mortality risk were due to shared household or behavioural characteristics.

Results

Volunteers were general more affluent, better educated and more religious than their non-volunteering peers; they also had a lower mortality risk [hazard ratio (HR)adj = 0.78: 95% confidence interval (CI) = 0.71, 0.85 for males and HRadj = 0.77: 95% CI = 0.68, 0.88 for females]. However, amongst cohort members who were not volunteers, having a partner who was a volunteer was not associated with a mortality advantage (HRadj = 1.01: 95% CI = 0.92, 1.11 for men and HRadj = 1.00: 95% CI = 0.88, 1.13 women).

Conclusions

This study provides further evidence that the lower mortality associated with volunteering is unlikely to be due to health selection or to residual confounding arising from unmeasured selection effects within households. It therefore increases the plausibility of a direct causal effect.

Structured mating: Patterns and implications

Genetic similarity of spouses can reflect factors influencing mate choice, such as physical/behavioral characteristics, and patterns of social endogamy. Spouse correlations for both genetic ancestry and measured traits may impact genotype distributions (Hardy Weinberg and linkage equilibrium), and therefore genetic association studies. Here we evaluate white spouse-pairs from the Framingham Heart Study (FHS) original and offspring cohorts (N = 124 and 755, respectively) to explore spousal genetic similarity and its consequences. Two principal components (PCs) of the genome-wide association (GWA) data were identified, with the first (PC1) delineating clines of Northern/Western to Southern European ancestry and the second (PC2) delineating clines of Ashkenazi Jewish ancestry. In the original (older) cohort, there was a striking positive correlation between the spouses in PC1 (r = 0.73, P = 3x10^-22) and also for PC2 (r = 0.80, P = 7x10^-29). In the offspring cohort, the spouse correlations were lower but still highly significant for PC1 (r = 0.38, P = 7x10^-28) and for PC2 (r = 0.45, P = 2x10^-39). We observed significant Hardy-Weinberg disequilibrium for single nucleotide polymorphisms (SNPs) loading heavily on PC1 and PC2 across 3 generations, and also significant linkage disequilibrium between unlinked SNPs; both decreased with time, consistent with reduced ancestral endogamy over generations and congruent with theoretical calculations. Ignoring ancestry, estimates of spouse kinship have a mean significantly greater than 0, and more so in the earlier generations. Adjusting kinship estimates for genetic ancestry through the use of PCs led to a mean spouse kinship not different from 0, demonstrating that spouse genetic similarity could be fully attributed to ancestral assortative mating. These findings also have significance for studies of heritability that are based on distantly related individuals (kinship less than 0.05), as we also demonstrate the poor correlation of kinship estimates in that range when ancestry is or is not taken into account.

We analyzed three generations of whites from the Framingham Heart Study (FHS) using genome-wide genotype data to characterize their genetic ancestry. By examination of spouse-pairs, we observed that individuals of Northern/Western European, Southern European and Ashkenazi ancestry preferentially chose spouses of the same ancestry, however, the degree of endogamy decreased in each successive generation, especially between Northern/Western and Southern Europeans. We then showed that the mating pattern results in Hardy-Weinberg disequilibrium (HWD) at ancestrally-informative SNPs, and also results in linkage disequilibrium (LD) between unlinked loci. The HWD and LD decrease as theoretically expected with the decrease in endogamy noted in each generation. In the FHS sample, spouse genetic similarity can be explained by ancestry-related assortative mating.

Close genetic relationships between a spousal pair with autism-affected children and high minor allele content in cases in autism-associated SNPs

Parents of children affected with autism spectrum disorders (ASD) often have mild forms of autistic-like characteristics. Past studies have focused on searching for individual genetic risk loci of ASD. Here we studied the overall properties of the genomes of ASD trios by using previously published genome-wide data for common SNPs. The pairwise genetic distance (PGD) between a spousal pair with ASD-affected children was found smaller than that of a random pair selected among the spouses in the ASD trios, and spousal relatedness correlated with severe forms of ASD. Furthermore, for a set of 970 ASD associated SNPs, cases showed higher homozygous minor allele content than parents. These results indicate new genetic elements in the broad phenotypes of parents with ASD-affected offspring and in ASD pathogenesis.

The Role of Genes and Environment in Degree of Partner Self-Similarity

Choice of romantic partner is an enormously important component of human life, impacting almost every facet of day-to-day existence, however; the processes underlying this choice are remarkably complex and have so far been largely resistant to scientific explanation. One consistent finding is that, on average, members of romantic dyads tend to be more alike than would be expected by chance. Selecting for self-similarity is at least partially driven by phenotypic matching wherein couples share similar phenotypes, and preferences for a number of these traits are partly genetically influenced (e.g., education, height, social attitudes and religiosity). This suggests that genetically influenced preferences for self-similarity might contribute to phenotypic matching (and thus assortative mating), but it has never been studied in actual couples. In the present study, we use a large sample of twins to model sources of variation in self-similarity between partners. Biometrical modelling revealed that very little of the variation in the tendency to assortatively mate across 14 traits was due to genetic effects (7 %) or the shared environment of twins (0 %).

Women and Alcohol Use Disorders: Factors That Lead to Harm

Women, alcohol, and alcohol use disorders are underresearched topics when compared with the plethora of literature exploring male alcohol consumption and its related harms. It is time to change the fact that women are underrepresented in research and programs targeting alcohol use disorders. Given the changing patterns of alcohol consumption by women, coupled with the fact that women experience a telescoping effect in alcohol-related harms, it is time that increasing attention be paid to the way gender influences the experience of alcohol-related harms, including the development of alcohol use disorders. Recovery-orientated systems are not possible without the voices of the consumers being heard. With this in mind, the purposes of this article are to explore factors that lead to alcohol-related harm in women and to highlight the gender-specific barriers to service engagement.

Test for association of common variants in GRM7 with alcohol consumption

Recent work using a mouse model has identified the glutamate metabotropic receptor 7 (Grm7) gene as a strong candidate gene for alcohol consumption. Although there has been some work examining the effect of human glutamate metabotropic receptor 7 (GRM7) polymorphisms on human substance use disorders, the majority of the work has focused on other psychiatric disorders such as ADHD, major depressive disorder, schizophrenia, bipolar disorder, panic disorder, and autism spectrum disorders. The current study aimed to evaluate evidence for association between GRM7 and alcohol behaviors in humans using a single nucleotide polymorphism (SNP) approach, as well as a gene-based approach. Using 1803 non-Hispanic European Americans (EAs) (source: the Colorado Center on Antisocial Drug Dependence [CADD]) and 1049 EA subjects from an independent replication sample (source: the Genetics of Antisocial Drug Dependence [GADD]), two SNPs in GRM7 were examined for possible association with alcohol consumption using two family-based association tests implemented in FBAT and QTDT. Rs3749380 was suggestively associated with alcohol consumption in the CADD sample (p = 0.010) with the minor T allele conferring risk. There was no evidence for association in the GADD sample. A gene-based test using four Genome-Wide Association Studies (GWAS) revealed no association between variation in GRM7 and alcohol consumption. This study had several limitations: the SNPs chosen likely do not tag expression quantitative trait loci; a human alcohol consumption phenotype was used, complicating the interpretation with respect to rodent studies that found evidence for a cis-regulatory link between alcohol preference and Grm7; and only common SNPs imputed in all four datasets were included in the gene-based test. These limitations highlight the fact that rare variants, some potentially important common signals in the gene, and regions farther upstream were not examined.

Effect of Marriage on Risk for Onset of Alcohol Use Disorder: A Longitudinal and Co-Relative Analysis in a Swedish National Sample

OBJECTIVE

The authors sought to clarify the relationship between marriage and risk for alcohol use disorder.

METHOD

The association between marital status and risk for first registration for alcohol use disorder in medical, criminal, and pharmacy registries was assessed in a population-based Swedish cohort (N=3,220,628) using longitudinal time-dependent survival and co-relative designs.

RESULTS

First marriage was associated with a substantial decline in risk for onset of alcohol use disorder in men (hazard ratio=0.41, 95% CI=0.40-0.42) and women (hazard ratio=0.27, 95% CI=0.26-0.28). This association was slightly stronger when the spouse had no lifetime alcohol use disorder, while marriage to a spouse with lifetime alcohol use disorder increased risk for subsequent alcohol use disorder registration in both men (hazard ratio=1.29, 95% CI=1.16-1.43) and women (hazard ratio=1.18, 95% CI=1.06-1.30). In both sexes, the protective effect of marriage was significantly stronger in those with than those without a family history of alcohol use disorder. In both men and women, the associations between marriage and risk for alcohol use disorder in cousins, half siblings, full siblings, and monozygotic twins discordant for marital status were as strong as that seen in the general population.

CONCLUSIONS

First marriage to a spouse with no lifetime alcohol use disorder is associated with a large reduction in risk for alcohol use disorder. This association cannot be explained by standard covariates or, as indicated by co-relative analyses, familial genetic or shared environmental confounders. These results are consistent with the hypothesis that the psychological and social aspects of marriage, and in particular health-monitoring spousal interactions, strongly protect against the development of alcohol use disorder. The protective effects of marriage on risk for alcohol use disorder are increased in those at high familial risk for alcoholism.

Patterns of Nonrandom Mating Within and Across 11 Major Psychiatric Disorders

IMPORTANCE

Psychiatric disorders are heritable, polygenic traits, which often share risk alleles and for which nonrandom mating has been suggested. However, despite the potential etiological implications, the scale of nonrandom mating within and across major psychiatric conditions remains unclear.

OBJECTIVE

To quantify the nature and extent of nonrandom mating within and across a broad range of psychiatric conditions at the population level.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort using Swedish population registers. Participants were all Swedish residents with a psychiatric diagnosis of interest (attention-deficit/hyperactivity disorder, autism spectrum disorder, schizophrenia, bipolar disorder, major depression, generalized anxiety disorder, agoraphobia, social phobia, obsessive-compulsive disorder, anorexia, or substance abuse), along with their mates. Individuals with select nonpsychiatric disorders (Crohn's disease, type 1 and type 2 diabetes mellitus, multiple sclerosis, or rheumatoid arthritis) were included for comparison. General population samples were also derived and matched 1:5 with each case proband. Inpatient and outpatient diagnostic data were derived from the Swedish National Patient Register (1973-2009), with analyses conducted between June 2014 and May 2015.

MAIN OUTCOMES AND MEASURES

Correlation in the diagnostic status of mates both within and across disorders. Conditional logistic regression was used to quantify the odds of each diagnosis in the mates of cases relative to matched population controls.

RESULTS

Across cohorts, data corresponded to 707 263 unique case individuals, with women constituting 45.7% of the full population. Positive correlations in diagnostic status were evident between mates. Within-disorder correlations were marginally higher (range, 0.11-0.48) than cross-disorder correlations (range, 0.01-0.42). Relative to matched populations, the odds of psychiatric case probands having an affected mate were significantly elevated. Differences in the magnitude of observed relationships were apparent by disorder (odds ratio range, 0.8-11.4). The number of comorbidities in a case proband was associated with the proportion of affected mates. These relationships were not apparent or weaker in magnitude among nonpsychiatric conditions (correlation range, -0.03 to 0.17).

CONCLUSIONS AND RELEVANCE

Nonrandom mating is evident in psychiatric populations both within specific disorders and across the spectrum of psychiatric conditions. This phenomenon may hold important implications for how we understand the familial transmission of these disorders and for psychiatric genetic research.

The variance shared across forms of childhood trauma is strongly associated with liability for psychiatric and substance use disorders

INTRODUCTION

Forms of childhood trauma tend to co-occur and are associated with increased risk for psychiatric and substance use disorders. Commonly used binary measures of trauma exposure have substantial limitations.

METHODS

We performed multigroup confirmatory factor analysis (CFA), separately by sex, using data from the Childhood Trauma (CT) Study's sample of twins and siblings (N = 2594) to derive three first-order factors (childhood physical abuse, childhood sexual abuse, and parental partner abuse) and, as hypothesized, one higher order, childhood trauma factor (CTF) representing a measure of their common variance.

RESULTS

CFA produced a good-fitting model in the CT Study; we replicated the model in the Comorbidity and Trauma (CAT) Study's sample (N = 1981) of opioid-dependent cases and controls. In both samples, first-order factors are moderately correlated (indicating they measure largely unique, but related constructs) and their loadings on the CTF suggest it provides a reasonable measure of their common variance. We examined the association of CTF score with risk for psychiatric and substance use disorders in these samples and the OZ-ALC GWAS sample (N = 1538) in which CT Study factor loadings were applied. We found that CTF scores are strongly associated with liability for psychiatric and substance use disorders in all three samples; estimates of risk are extremely consistent across samples.

CONCLUSIONS

The CTF is a continuous, robust measure that captures the common variance across forms of childhood trauma and provides a means to estimate shared liability while avoiding multicollinearity.

Discrepant Patterns of Heavy Drinking, Marijuana Use, and Smoking and Intimate Partner Violence: Results From the California Community Health Study of Couples

This study analyzed whether discrepant (husband or wife use only) or concordant (both partners use) patterns of heavy drinking, marijuana use, and smoking are associated with increased risk for male-to-female partner violence and female-to-male partner violence among adult couples. Based on a geographic sample of married or cohabiting couples residing in 50 California cities, logistic regression analyses were conducted using dyadic data on past-year partner violence, binge drinking and frequency of intoxication, marijuana use, and smoking. When all substance use patterns were included simultaneously, wife-only heavy drinking couples were at elevated risk for male-to-female partner violence, as were concordant marijuana-using couples. Husband-only marijuana discrepant couples were at increased risk for female-to-male partner violence. Further research is needed to explore the processes by which discrepant and concordant substance use patterns may contribute to partner aggression.

Human mate selection and addiction: a conceptual critique

The authors review past work on modeling human mate selection, and suggest, using illustrations from existing literature on the impact of alcoholism on relationship formation and dissolution and reproduction, that the challenges of adequately characterizing human mate selection have not yet been overcome. Some paths forwards are suggested.

Social contexts of remission from DSM-5 alcohol use disorder in a high-risk sample

BACKGROUND

Measures of social context, such as marriage and religious participation, are associated with remission from alcohol use disorders (AUDs) in population-based and treatment samples, but whether these associations hold among individuals at high familial risk for AUD is unknown. This study tests associations of measures of social context and treatment with different types of remission from DSM-5 AUD in a high-risk sample.

METHODS

Subjects were 686 relatives of probands (85.7% first-degree) who participated in a high-risk family study of alcohol dependence. All subjects met criteria for AUD at baseline and were re-interviewed 5 years later. Follow-up status was categorized as persistent AUD, high-risk drinking, remitted low-risk drinking, and abstinence. Social context measures were defined as stable or changing from baseline to follow-up, and their bivariate and multivariate associations with follow-up status were tested.

RESULTS

At follow-up, 62.8% of subjects had persistent AUD, 6.4% were high-risk drinkers, 22.2% were remitted low-risk drinkers, and 8.6% were abstinent. Birth of first child during the interval was the only measure of social context associated with remitted low-risk drinking and was significant for women only. Abstinent remission was characterized by being stably separated or divorced for women, new marriage for both sexes, experiencing low levels of family support and high levels of friend support, and receiving treatment. High-risk drinkers were more likely than individuals with persistent AUD to have a stable number of children and to have been recently unemployed.

CONCLUSIONS

The social contexts accompanying different types of remission in this high-risk sample resemble those found in population-based and clinical samples. Low-risk drinkers resemble natural remitters from population-based samples who change their drinking habits with life transitions. Abstainers resemble clinical samples in marital context, support from friends, and treatment. High-risk drinkers appear to continue to experience negative consequences of heavy drinking.

Alcohol dependence and reproductive timing in African and European ancestry women: findings in a midwestern twin cohort

OBJECTIVE

We examined associations between reproductive onset and history of alcohol dependence (AD) in 475 African ancestry (AA) and 2,865 European or other ancestry (EA) female twins.

METHOD

Participants were drawn from a U.S. midwestern birth cohort study of like-sex female twin pairs born between 1975 and 1985, ages 21-32 as of last completed assessment. Cox proportional hazards regression models were estimated predicting age at first childbirth from history of AD, separately by race/ethnicity, without and with adjustment for sociodemographic characteristics, body mass index, history of other substance involvement, psychopathology, and family and childhood risks.

RESULTS

Among EA twins, AD predicted early childbearing through age 17 and delayed childbearing from age 25 onward; in adjusted models, AD was associated with overall delayed childbearing. Among AA twins, reproductive timing and AD were not significantly related in either unadjusted or adjusted models.

CONCLUSIONS

Findings for twins of European ancestry are consistent with well-documented links between early alcohol mis/use and teenage parenting as well as delays in childbearing associated with drinking-related reproductive and relationship difficulties. Extension of analyses to other racial/ethnic groups of sufficient sample size remains important.

"Drinking buddies" and alcohol dependence symptoms among African American men and women in Baltimore, MD

BACKGROUND

Social network characteristics have been found to be associated with a variety of risky behaviors, including alcohol consumption. This study assessed the relationships between the characteristics of drinking buddies and alcohol dependence symptoms among a sample of African American men and women.

METHODS

This is a cross-sectional study using baseline data from 721 impoverished African American men and women participating in an HIV prevention study in Baltimore, MD. Alcohol dependence symptoms were assessed through the Alcohol Use Disorders Identification Test (AUDIT) and was defined as AUDIT score≥13 for females and AUDIT score≥15 for males. Logistic regression models with generalized estimating equations (GEE) using network member as the unit of analysis were conducted to assess the associations between the gender or relationship (i.e., kin, non-kin or sex partner) of the drinking buddies and the participants' alcohol dependence symptoms.

RESULTS

Approximately 22% of the participants had alcohol dependence symptoms. Among male participants, alcohol dependence symptoms were associated with having drinking buddies who were sex partners (AOR: 2.41; 95%CI: 1.32, 4.39) or who were female (AOR: 2.29; 95%CI: 1.29, 4.05). Among female participants, association between the presence of drinking buddy and alcohol dependence symptoms did not depend on the types of relationship or the gender of the drinking buddy.

CONCLUSIONS

Social network characteristics with respect to alcohol dependence symptoms vary according to the type of relationship or the gender of the drinking buddies, especially among men. Gender-specific norm-based interventions may be a useful strategy to decrease drink problems.

An exploratory investigation of marital functioning and order of spousal onset in couples concordant for psychopathology

Individuals with a psychiatric disorder are significantly more likely to have a spouse with a clinical diagnosis--marital concordance. We used a community sample of 304 couples concordant for either major depressive disorder (MDD) or substance use disorders (SUDs) to examine the relationship between marital functioning and gendered patterns of mental health diagnosis onset. For SUD concordance, couples in which wives onset before husbands--despite typical later onset for men--reported lower levels of marital satisfaction compared with couples in which the husband onset first. For MDD concordance, couples in which husbands onset with depression before wives--despite typical later onset for men--reported lower levels of marital satisfaction. These results suggest that for couples concordant for mental diagnoses, it is most problematic for marital functioning for one partner to have an atypically early onset. Implications for treatment targets in marital therapy are discussed.