Assortative mating for major psychiatric diagnoses in two population-based samples

Non-random Mating Patterns in Education, Mental, and Somatic Health: A Population Study on Within- and Cross-Trait Associations

Partners resemble each other on many traits, such as health and education. The traits are usually studied one by one in data from established couples and with potential participation bias. We studied all Norwegian parents who had their first child between 2016 and 2020 (N=187,926) and the siblings of these parents. We analysed grade point averages at age 16 (GPA), educational attainment (EA), and medical records with diagnostic data on 10 mental and 10 somatic health conditions measured 10 to 5 years before childbirth. We found stronger partner similarity in mental (median r=0.14) than in somatic health conditions (median r=0.04), with ubiquitous cross-trait correlations for mental health conditions (median r=0.13). GPA correlated 0.43 and EA 0.47 between partners. High GPA or EA was associated with better mental (median r=-0.16) and somatic (median r=-0.08) health in partners. Elevated correlations for mental health (median r=0.25) in established couples indicated convergence. Analyses of siblings and in-laws revealed deviations from direct assortment, suggesting instead indirect assortment based on related traits. Adjusting for GPA and EA reduced partner correlations in health with 30-40%. This has implications for the distribution of risk factors among children, for genetic studies, and for studies of intergenerational transmission.

The Nature of the Familial Risk for Psychosis in Bipolar Disorder

BACKGROUND AND HYPOTHESIS

To clarify whether the familial liability to psychosis associated with bipolar disorder (BD) is nonspecific or has a greater effect on risk for psychosis in cases with prominent mood symptoms and/or a remitting course.

STUDY DESIGN

We examined, in 984 809 offspring raised in intact families in Sweden, born 1980-1996 and followed-up through 2018, by multivariable Cox proportional hazards regression, risk in offspring of parents with BD for 7 psychotic disorders: Psychotic MD (PMD), psychotic BD (PBD), schizoaffective disorder (SAD), acute psychoses, psychosis NOS, delusional disorder (DD) and schizophrenia (SZ). Diagnoses were obtained from national registers.

STUDY RESULTS

In the offspring of BD parents, the hazard ratios (HR) for these 7 disorders formed an inverted U-shaped curve, rising from 2.98 for PMD, to peak at 4.49 for PBD and 5.25 for SAD, and then declining to a HR of 3.48 for acute psychoses and 3.22 for psychosis NOS, to a low of 2.19 for DD and 2.33 for SZ. A similar pattern of risks was seen in offspring of mothers and fathers affected with BD and in offspring predicted from age at onset in their BD parent.

CONCLUSIONS

The BD-associated risk for psychosis impacts most strongly on mood disorders, moderately on episodic psychotic syndromes, and least on chronic psychotic disorders. These results support prior clinical studies suggesting a qualitative difference in the familial substrate for psychosis occurring in BD and SZ.

The collaborative study on the genetics of alcoholism: Genetics

This review describes the genetic approaches and results from the family-based Collaborative Study on the Genetics of Alcoholism (COGA). COGA was designed during the linkage era to identify genes affecting the risk for alcohol use disorder (AUD) and related problems, and was among the first AUD-focused studies to subsequently adopt a genome-wide association (GWAS) approach. COGA's family-based structure, multimodal assessment with gold-standard clinical and neurophysiological data, and the availability of prospective longitudinal phenotyping continues to provide insights into the etiology of AUD and related disorders. These include investigations of genetic risk and trajectories of substance use and use disorders, phenome-wide association studies of loci of interest, and investigations of pleiotropy, social genomics, genetic nurture, and within-family comparisons. COGA is one of the few AUD genetics projects that includes a substantial number of participants of African ancestry. The sharing of data and biospecimens has been a cornerstone of the COGA project, and COGA is a key contributor to large-scale GWAS consortia. COGA's wealth of publicly available genetic and extensive phenotyping data continues to provide a unique and adaptable resource for our understanding of the genetic etiology of AUD and related traits.

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.

Origins of spousal cross-concordance for psychiatric disorders: a test of the social stress theory for alcohol use disorder

BACKGROUND

The authors sought to clarify the impact of spousal psychiatric disorders of differing severity [major depression or anxiety disorders (DAD) v. bipolar disorder or nonaffective psychosis (BPN)] on proband risk for alcohol use disorder (AUD) during marriage.

METHODS

In a Swedish cohort (N = 744 628), associations between spousal DAD and BPN and proband AUD were estimated with Cox proportional hazards; associations between parental AUD, proband premarital AUD, and spousal lifetime DAD and BPN were estimated with logistic regression; and whether spousal DAD or BPN causally increased risk for AUD was evaluated with frailty models.

RESULTS

Spousal premarital DAD, spousal marital-onset DAD, and spousal BPN (premarital or marital-onset) were associated with proband AUD during marriage [hazard ratios (HR) range 1.44-3.72]. Those with a parental or premarital history of AUD (v. without) were more likely to marry a spouse with DAD or BPN (odds ratios 1.22-2.77). Moving from an unaffected first spouse to a DAD-affected second spouse increased AUD risk in males (HR 2.90). Moving from an unaffected first spouse to a BPN-affected second spouse increased AUD risk (HRmales 3.96; HRfemales 5.64). Moving to an unaffected second spouse from a DAD-affected first spouse decreased AUD risk, with stronger evidence in females compared to males (HRmales 0.59; HRfemales 0.28).

CONCLUSIONS

Associations between spousal DAD or BPN and proband AUD reflect both selection and causal effects. Marriage to a BPN-affected spouse has a particularly strong effect on AUD risk, with more modest effects for spousal DAD.

Adult Survivors of Child Sexual Abuse Draw and Describe Their Experiences of Dissociation

The paper examined how dissociation is experienced and manifested in the drawings and narratives of female survivors of childhood sexual abuse (CSA) diagnosed with dissociative identity disorder. Fifteen Israeli women filled out a self-report questionnaire consisting of demographics, traumatic events, and dissociation severity. Then, they were asked to draw a dissociation experience and provide a narrative. The results indicated that experiencing CSA was highly correlated with indicators such as the level of fragmentation, the figurative style, as well as with the narrative. Two main themes emerged: a constant movement between internal and external worlds, and distorted perceptions of time and space.

Human height: a model common complex trait

CONTEXT

Like other complex phenotypes, human height reflects a combination of environmental and genetic factors, but is notable for being exceptionally easy to measure. Height has therefore been commonly used to make observations later generalised to other phenotypes though the appropriateness of such generalisations is not always considered.

OBJECTIVES

We aimed to assess height's suitability as a model for other complex phenotypes and review recent advances in height genetics with regard to their implications for complex phenotypes more broadly.

METHODS

We conducted a comprehensive literature search in PubMed and Google Scholar for articles relevant to the genetics of height and its comparatibility to other phenotypes.

RESULTS

Height is broadly similar to other phenotypes apart from its high heritability and ease of measurment. Recent genome-wide association studies (GWAS) have identified over 12,000 independent signals associated with height and saturated height's common single nucleotide polymorphism based heritability of height within a subset of the genome in individuals similar to European reference populations.

CONCLUSIONS

Given the similarity of height to other complex traits, the saturation of GWAS's ability to discover additional height-associated variants signals potential limitations to the omnigenic model of complex-phenotype inheritance, indicating the likely future power of polygenic scores and risk scores, and highlights the increasing need for large-scale variant-to-gene mapping efforts.

Genetic and environmental sources of familial resemblance in anxiety: a nuclear twin family design

BACKGROUND

A dominant feature of anxiety disorders is familial aggregation. However, the underlying mechanisms of between- and within-generational anxiety resemblance remain poorly understood. By disentangling the genetic v. environmental sources of familial resemblance in anxiety, we can help prevent within-family transmission of anxiety disorders. Therefore, data from both parents and twins are needed to obtain unbiased and detailed estimations of genetic and environmental sources of similarity between family members.

METHODS

We examined data from 991 families with same-sex twins. Trait anxiety in twins was assessed via self-report and parent report, while parental trait anxiety was assessed via self-report. We established a nuclear twin family model and estimated genetic and environmental variances using two survey waves.

RESULTS

The results suggested that additive genetic (A), dominant genetic (D), and non-shared environmental (E) influences significantly contributed to trait anxiety, whereas familial environmental influences (F) and passive gene-environment correlations (rGE) did not. Sibling environmental influences (S) were only found in self-report data, and increased when genetic influences decreased from Wave 1 to Wave 2.

CONCLUSIONS

Our study highlights the important role of broad heritability in intrafamilial trait anxiety similarity. Parent-child resemblance occurred primarily due to shared genetic makeup rather than direct environmental transmission. Sibling-specific environments, as the only source of shared environments, need further investigation. These findings have both theoretical and practical significance for anxiety disorders. Future research can expand our understanding by examining the gene-environment interplay and sex differences.

Within- and cross-mental health disorder correlations in husband-and-wife pairs

BACKGROUND

Mental health disorders can adversely affect relationships and are heritable. Yet, there is a high prevalence of mental illness in spouses and partners of those with mental illness. This study will assess within- and cross-mental health disorder correlations in husband-and-wife pairs.

METHODS

A cross-sectional study design was employed using medical claims data from the Deseret Mutual Benefit Administrators (DMBA), linked to demographic information from employee eligibility files, 2020. Analyses involved 21,027 contract holders aged 18-64 (68.6% male, 31.4% female), with sub-analyses on 16,543 married individuals. Summary statistics, as well as rates, and rate ratios adjusted for age, sex, and dependent child status were calculated to describe the data.

RESULTS

The rate of stress is 19.2%, anxiety is 26.4%, and depression is 23.6% in spouses of contract holders with the same respective disorders. Rates of stress, anxiety, and depression in a spouse are greatest if the contract holder has schizophrenia. Rates of mental illness in wives of male contract holders experiencing mental health disorders tend to be greater than the rates of mental illness in husbands of female contract holders experiencing mental health disorders. Rates of stress, anxiety, and depression in spouses of contract holders tend to be 2-3 times greater when the contract holder has a mental health disorder, after adjusting for the contract holder's age, sex, dependent child status, and difference in age within husband-and-wife pairs. However, differences in the magnitude of observed associations vary. The rate of a spouse having stress is 5.5 times greater if the contract holder has schizophrenia (vs. does not have schizophrenia), whereas the rate of a spouse having stress is 1.4 times greater if the contract holder has sleep apnea (vs. does not have sleep apnea).

CONCLUSION

Mental health disorders in spouses of contract holders are greater if the contract holder has a mental health disorder, more so when the contract holder has more serious mental illness. Both within- and cross-mental disorder correlations exist. These results have implications on relationship quality and the mental health of offspring.

Variation in depressive symptom trajectories in a large sample of couples

The occurrence of depression is influenced by social relationships, however, most studies focus on individuals, not couples. We aimed to study how depressive symptoms of couples evolve over time and determine, which characteristics are associated with their distinct trajectories. A multi-centric cohort sample of 11,136 heterosexual couples (mean age = 60.76) from 16 European countries was followed for up to 12 years (SHARE study). Information on depressive symptoms measured by EURO-D scale was collected every 2 years. Dyadic growth mixture modeling extracted four distinct classes of couples: both non-depressed (76.91%); only women having consistently high depressive symptoms while men having consistently low depressive symptoms (8.08%); both having increasing depressive symptoms (7.83%); and both having decreasing depressive symptoms (7.18%). Couples with increasing depressive symptoms had the highest prevalence of relationship dissolution and bereavement. In comparison to the nondepressed class, individuals with any depressive symptoms were less psychologically and physically well. Our results suggest that distinct mechanisms are responsible for couples' various longitudinal trajectories of depressive symptoms.

Polygenic risk for mental disorder reveals distinct association profiles across social behaviour in the general population

Many mental health conditions present a spectrum of social difficulties that overlaps with social behaviour in the general population including shared but little characterised genetic links. Here, we systematically investigate heterogeneity in shared genetic liabilities with attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD), bipolar disorder (BP), major depression (MD) and schizophrenia across a spectrum of different social symptoms. Longitudinally assessed low-prosociality and peer-problem scores in two UK population-based cohorts (4-17 years; parent- and teacher-reports; Avon Longitudinal Study of Parents and Children(ALSPAC): N ≤ 6,174; Twins Early Development Study(TEDS): N ≤ 7,112) were regressed on polygenic risk scores for disorder, as informed by genome-wide summary statistics from large consortia, using negative binomial regression models. Across ALSPAC and TEDS, we replicated univariate polygenic associations between social behaviour and risk for ADHD, MD and schizophrenia. Modelling variation in univariate genetic effects jointly using random-effect meta-regression revealed evidence for polygenic links between social behaviour and ADHD, ASD, MD, and schizophrenia risk, but not BP. Differences in age, reporter and social trait captured 45-88% in univariate effect variation. Cross-disorder adjusted analyses demonstrated that age-related heterogeneity in univariate effects is shared across mental health conditions, while reporter- and social trait-specific heterogeneity captures disorder-specific profiles. In particular, ADHD, MD, and ASD polygenic risk were more strongly linked to peer problems than low prosociality, while schizophrenia was associated with low prosociality only. The identified association profiles suggest differences in the social genetic architecture across mental disorders when investigating polygenic overlap with population-based social symptoms spanning 13 years of child and adolescent development.

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.

Associations Between Traumatic Stress, Brain Volumes and Post-traumatic Stress Disorder Symptoms in Children: Data from the ABCD Study

Reduced volumes in brain regions of interest (ROIs), primarily from adult samples, are associated with posttraumatic stress disorder (PTSD). We extended this work to children using data from the Adolescent Brain Cognitive Development (ABCD) Study® (N = 11,848; M_age = 9.92). Structural equation modeling and an elastic-net (EN) machine-learning approach were used to identify potential effects of traumatic events (TEs) on PTSD symptoms (PTSDsx) directly, and indirectly via the volumes 300 subcortical and cortical ROIs. We then estimated the genetic and environmental variation in the phenotypes. TEs were directly associated with PTSDsx (r = 0.92) in children, but their indirect effects (r < 0.0004)-via the volumes of EN-identified subcortical and cortical ROIs-were negligible at this age. Additive genetic factors explained a modest proportion of the variance in TEs (23.4%) and PTSDsx (21.3%), and accounted for most of the variance of EN-identified volumes of four of the five subcortical (52.4-61.8%) three of the nine cortical ROIs (46.4-53.3%) and cerebral white matter in the left hemisphere (57.4%). Environmental factors explained most of the variance in TEs (C = 61.6%, E = 15.1%), PTSDsx (residual-C = 18.4%, residual-E = 21.8%), right lateral ventricle (C = 15.2%, E = 43.1%) and six of the nine EN-identified cortical ROIs (C = 4.0-13.6%, E = 56.7-74.8%). There is negligible evidence that the volumes of brain ROIs are associated with the indirect effects of TEs on PTSDsx at this age. Overall, environmental factors accounted for more of the variation in TEs and PTSDsx. Whereas additive genetic factors accounted for most of the variability in the volumes of a minority of cortical and in most of subcortical ROIs.

How important are parents in the development of child anxiety and depression? A genomic analysis of parent-offspring trios in the Norwegian Mother Father and Child Cohort Study (MoBa)

BACKGROUND

Many studies detect associations between parent behaviour and child symptoms of anxiety and depression. Despite knowledge that anxiety and depression are influenced by a complex interplay of genetic and environmental risk factors, most studies do not account for shared familial genetic risk. Quantitative genetic designs provide a means of controlling for shared genetics, but rely on observed putative exposure variables, and require data from highly specific family structures.

METHODS

The intergenerational genomic method, Relatedness Disequilibrium Regression (RDR), indexes environmental effects of parents on child traits using measured genotypes. RDR estimates how much the parent genome influences the child indirectly via the environment, over and above effects of genetic factors acting directly in the child. This 'genetic nurture' effect is agnostic to parent phenotype and captures unmeasured heritable parent behaviours. We applied RDR in a sample of 11,598 parent-offspring trios from the Norwegian Mother, Father and Child Cohort Study (MoBa) to estimate parental genetic nurture separately from direct child genetic effects on anxiety and depression symptoms at age 8. We tested for mediation of genetic nurture via maternal anxiety and depression symptoms. Results were compared to a complementary non-genomic pedigree model.

RESULTS

Parental genetic nurture explained 14% of the variance in depression symptoms at age 8. Subsequent analyses suggested that maternal anxiety and depression partially mediated this effect. The genetic nurture effect was mirrored by the finding of family environmental influence in our pedigree model. In contrast, variance in anxiety symptoms was not significantly influenced by common genetic variation in children or parents, despite a moderate pedigree heritability.

CONCLUSIONS

Genomic methods like RDR represent new opportunities for genetically sensitive family research on complex human traits, which until now has been largely confined to adoption, twin and other pedigree designs. Our results are relevant to debates about the role of parents in the development of anxiety and depression in children, and possibly where to intervene to reduce problems.

Intergenerational transmission: Theoretical and methodological issues and an introduction to four Dutch cohorts

Behaviors, traits and characteristics are transmitted from parents to offspring because of complex genetic and non-genetic processes. We review genetic and non-genetic mechanisms of intergenerational transmission of psychopathology and parenting and focus on recent methodological advances in disentangling genetic and non-genetic factors. In light of this review, we propose that future studies on intergenerational transmission should aim to disentangle genetic and non-genetic transmission, take a long-term longitudinal perspective, and focus on paternal and maternal intergenerational transmission. We present four large longitudinal cohort studies within the Consortium on Individual Development, which together address many of these methodological challenges. These four cohort studies aim to examine the extent to which genetic and non-genetic transmission from the parental generation shapes parenting behavior and psychopathology in the next generation, as well as the extent to which self-regulation and social competence mediate this transmission. Conjointly, these four cohorts provide a comprehensive approach to the study of intergenerational transmission.

Causes of Variation in Food Preference in the Netherlands

Our current society is characterized by an increased availability of industrially processed foods with high salt, fat and sugar content. How is it that some people prefer these unhealthy foods while others prefer more healthy foods? It is suggested that both genetic and environmental factors play a role. The aim of this study was to (1) identify food preference clusters in the largest twin-family study into food preference to date and (2) determine the relative contribution of genetic and environmental factors to individual differences in food preference in the Netherlands. Principal component analysis was performed to identify the preference clusters by using data on food liking/disliking from 16,541 adult multiples and their family members. To estimate the heritability of food preference, the data of 7833 twins were used in structural equation models. We identified seven food preference clusters (Meat, Fish, Fruits, Vegetables, Savory snacks, Sweet snacks and Spices) and one cluster with Drinks. Broad-sense heritability (additive [A] + dominant [D] genetic factors) for these clusters varied between .36 and .60. Dominant genetic effects were found for the clusters Fruit, Fish (males only) and Spices. Quantitative sex differences were found for Meat, Fish and Savory snacks and Drinks. To conclude, our study convincingly showed that genetic factors play a significant role in food preference. A next important step is to identify these genes because genetic vulnerability for food preference is expected to be linked to actual food consumption and different diet-related disorders.

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.

The genetics of bipolar disorder

Bipolar disorder (BD) is one of the most heritable mental illnesses, but the elucidation of its genetic basis has proven to be a very challenging endeavor. Genome-Wide Association Studies (GWAS) have transformed our understanding of BD, providing the first reproducible evidence of specific genetic markers and a highly polygenic architecture that overlaps with that of schizophrenia, major depression, and other disorders. Individual GWAS markers appear to confer little risk, but common variants together account for about 25% of the heritability of BD. A few higher-risk associations have also been identified, such as a rare copy number variant on chromosome 16p11.2. Large scale next-generation sequencing studies are actively searching for other alleles that confer substantial risk. As our understanding of the genetics of BD improves, there is growing optimism that some clear biological pathways will emerge, providing a basis for future studies aimed at molecular diagnosis and novel therapeutics.

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.

Severe mood disorders and schizophrenia in the adult offspring of antenatally depressed mothers in the Northern Finland 1966 Birth Cohort: Relationship to parental severe mental disorder

BACKGROUND

Maternal antenatal depression may alter offspring neurodevelopment, but long follow-up studies are lacking. We studied the risks for mood disorders and schizophrenia in adult offspring of antenatally depressed mothers, taking account parental severe mental disorders.

METHODS

In the general population-based Northern Finland 1966 Birth Cohort with 12,058 children, 13.9% of the mothers reported themselves depressed at mid-gestation. The offspring were followed 43 years. Severe mood disorders and schizophrenia in the offspring and severe mental disorders in the parents were detected using the Care Register for Healthcare. Maternal smoking during pregnancy, perinatal complications, fathers´ social class, family type at birth, and grand multiparity were considered as confounding variables.

RESULTS

The offspring of antenatally depressed mothers had an elevated risk for depression (adjusted OR 1.5; 95% CI 1.03-2.2), compared to cohort members without maternal antenatal depressed mood. The offspring with maternal antenatal depressed mood and parental severe mental disorder had markedly elevated risks for depression (3.3; 1.8-6.2), and schizophrenia (3.9; 2.0-7.5), compared to the offspring without one or both of these risk factors.

LIMITATIONS

Maternal antenatal depressed mood was determined by one question and did not necessarily signify a clinical condition. Data on maternal postnatal mood was not available.

CONCLUSION

The offspring with maternal antenatal depressed mood and parental severe mental disorder had high risk for depression and schizophrenia. Early interventions in parental severe mental disorder might present an opportunity for decreasing the risk for mood disorders and schizophrenia in the offspring.

Early childhood aggressive behaviour: Negative interactions with paternal antisocial behaviour and maternal postpartum depressive symptoms across two international cohorts

Background

Early childhood aggressive behaviour is a predictor of future violence. Therefore, identifying risk factors for children’s aggressive behaviour is important in understanding underlying mechanisms. Maternal postpartum depression is a known risk factor. However, little research has focused on the influence of paternal behaviour on early childhood aggression and its interaction with maternal postpartum depression.

Methods

This study was performed in two cohorts: the Fathers Project, in the United Kingdom (n = 143) and the Generation R Study, in The Netherlands (n = 549). In both cohorts, we related paternal antisocial personality (ASP) traits and maternal postpartum depressive (PPD) symptoms to childhood aggressive behaviour at age two (Fathers Project) and age three (Generation R Study). We additionally tested whether the presence of paternal ASP traits increased the association between maternal PPD–symptoms and early childhood aggression.

Results

The association between paternal ASP traits and early childhood aggressive behaviour, corrected for maternal PPD-symptoms, was similar in magnitude between the cohorts (Fathers Project: standardized β = 0.12, p = 0.146; Generation R: β = 0.14, p = 0.001), although the association was not statistically significant in the Fathers Project. Strikingly, and in contrast to our expectations, there was evidence of a negative interaction between paternal ASP traits and maternal PPD-symptoms on childhood aggressive behaviour (Fathers Project: β = −0.20, p = 0.020; Generation R: β = −0.09, p = 0.043) in both studies. This meant that with higher levels of paternal ASP traits the association between maternal PPD-symptoms and childhood aggressive behaviour was less and vice versa.

Conclusions

Our findings stress the importance of including both maternal and paternal psychopathology in future studies and interventions focusing on early childhood aggressive behaviour.

Associations between loneliness and personality are mostly driven by a genetic association with Neuroticism

OBJECTIVE

Loneliness is an aversive response to a discrepancy between desired and actual social relationships and correlates with personality. We investigate the relationship of loneliness and personality in twin family and molecular genetic data.

METHOD

Phenotypic correlations between loneliness and the Big Five personality traits were estimated in 29,625 adults, and in a group with genome-wide genotype data (N = 4,222), genetic correlations were obtained. We explored whether genetic correlations may reflect causal relationships by investigating within monozygotic twin pair differences (N_pairs  = 2,662), by longitudinal within-subject changes in personality and loneliness (N = 4,260-9,238 longitudinal comparisons), and by longitudinal cross-lagged panel analyses (N = 15,628). Finally, we tested whether genetic correlations were due to cross-trait assortative mating (N_{spouse pairs}  = 4,436).

RESULTS

The strongest correlations with loneliness were observed for Neuroticism (r = .55) and Extraversion (r = -.33). Only Neuroticism showed a high correlation with loneliness independent of other personality traits (r = .50), so follow-up analyses focused on Neuroticism. The genetic correlation between loneliness and Neuroticism from genotyped variants was .71; a significant reciprocal causal relationship and nonsignificant cross-trait assortative mating imply that this is at least partly due to mediated pleiotropy.

CONCLUSIONS

We show that the relationship between loneliness and personality is largely explained by its relationship with Neuroticism, which is substantially genetic in nature.

Associations Between Divorce and Onset of Drug Abuse in a Swedish National Sample

Rates of drug abuse are higher among divorced individuals than among those who are married, but it is not clear whether divorce itself is a risk factor for drug abuse or whether the observed association is confounded by other factors. We examined the association between divorce and onset of drug abuse in a population-based Swedish cohort born during 1965-1975 (n = 651,092) using Cox proportional hazards methods, with marital status as a time-varying covariate. Potential confounders (e.g., demographics, adolescent deviance, and family history of drug abuse) were included as covariates. Parallel analyses were conducted for widowhood and drug-abuse onset. In models with adjustments, divorce was associated with a substantial increase in risk of drug-abuse onset in both sexes (hazard ratios > 5). Co-relative analyses (among biological relatives) were consistent with a partially causal role of divorce on drug-abuse onset. Widowhood also increased risk of drug-abuse onset, although to a lesser extent. Divorce is a potent risk factor for onset of drug abuse, even after adjusting for deviant behavior in adolescence and family history of drug abuse. The somewhat less-pronounced association with widowhood, particularly among men, suggests that the magnitude of association between divorce and drug abuse may not be generalizable to the end of a relationship.

The genetic and environmental architecture of substance use development from early adolescence into young adulthood: a longitudinal twin study of comorbidity of alcohol, tobacco and illicit drug use

AIMS

To investigate how use of alcohol, illicit drugs and tobacco come from substance-specific pathways and from pathways general to all three substances through adolescent development.

DESIGN

Analysis of population-based survey. Adolescent twins reported alcohol use (AU), tobacco use (TU) and illicit drug use (IDU) in three waves (2006, 2008, 2010). Restructuring data by age allowed for variance decomposition into age- and substance-specific and common genetic and environmental variance components.

SETTING

Norway.

PARTICIPANTS

Seven national twin birth cohorts from 1988 to 1994, totalling 1483 pairs (558 monozygotic; 925 dizygotic, same and opposite sex).

MEASUREMENTS

Six-point Likert scores of AU, TU and IDU on items from the Monitoring the Future Study.

FINDINGS

Substance use was found to be highly heritable; a²  = 0.73 [95% confidence interval (CI) = 0.61-0.94] for AU, a²  = 0.36 (CI = 0.18-0.52); d²  = 0.49 (95% CI = 0.29-0.62) for IDU and a²  = 0.46 (95% CI = 0.23-0.54); d²  = 0.05 (95% CI = 0.00-0.07) for TU during the whole adolescence period. General substance use (GSU) was also highly heritable at each age and averaged a²  = 0.57 (95% CI = 0.48-0.66). There was a high genetic carry-over from earlier age to later age. Genetic effects on GSU at ages 12-14 years were still detectable 4 years later. New substance (general and specific)-genetic effects also appeared. IDU demonstrated significant non-additive genetic effects (ages 12-14 years). Shared environment had a small impact on AU only. There was almost no non-shared environmental carry-over from age to age, the effect probably due partly to reliability deficiency. Common genetic effects among substance and substance-specific genetic effects were observed at each age-period.

CONCLUSIONS

Among Norwegian adolescents, there appear to be strong genetic effects on both substance-specific and comorbid use of alcohol, illicit drugs and tobacco; individual differences in alcohol use can be explained partially by family background.

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.

Homogamy in Masculinity-Femininity Is Positively Linked to Relationship Quality in Gay Male Couples from the Czech Republic

The main aims of this research were to test the similarity of masculinity-femininity in long-term male same-sex couples from the Czech Republic and to examine whether this similarity predicts higher relationship quality. In Study 1, participants (N = 30) and their partners completed the Dyadic Adjustment Scale (DAS) and the Childhood Gender Nonconformity Scale (CGN). In Study 2, participants (N = 40) and their partners completed DAS and the Gender Diagnosticity Scale (GD). Results showed that the partners were no more alike than individuals paired at random in their CGN or GD, but greater similarity in CGN between partners increased Dyadic Cohesion (r = -.41 [-.71, -.02]) and Affectional Expression (r = -.38 [-.60, -.13]). Our results add to previous evidence showing that similarity in same-sex couples increased relationship quality. Although, on average, gay men were not coupled on the basis of homogamy in gender roles, their relationship quality is linked to the gender egalitarian model rather than to the gender stratified one. Thus, a widespread stereotype suggesting that same-sex partners are divided by different gender roles seems to be, at least in our sample from a Western society, rather incorrect.

Eriksonian intimacy development, relationship satisfaction, and depression in gay male couples

Research suggests connections or links between the mental health of both partners in a romantic relationship, as partners often report similar mental health problems, with implications for relationship functioning. The current study utilized the framework of interdependence theory to explore associations among intimacy development, as conceptualized by Erikson, relationship satisfaction, and depression in a sample of 128 same-sex male couples. In each couple, one partner was recruited first through active or passive outreach conducted online and in-person, and after completion of the online survey, was then invited to send his partner a link to the study. The 256 male respondents (mean age = 32.6 years) all reported a U.S. residence and had an average relationship length of five years. Utilizing the Actor-Partner Interdependence Model, analyses indicated that participants' intimacy development directly predicted their own relationship satisfaction (B = 1.84, p< .01) as well as their partner's relationship satisfaction (B = 1.61, p<.01). Similarly, both the actor (B = -0.04, p< .01) and partner (B = -0.04, p< .05) effects of relationship satisfaction on depression were significant. Consistent with the interdependent concept of joint control, three indirect pathways linked Eriksonian intimacy to depression through relationship satisfaction. These findings suggest that individual development may become linked to mental health through pathways involving dyadic functioning. This pattern implies highly inter-connected links between the intra-personal and inter-personal, which have implications for mental health intervention with gay men in relationships.

Parallel contagion phenomenon of concordant mental disorders among married couples: a nationwide cohort study

BACKGROUND

The aggregation of mental disorders in couples, as reported by prior research, indicates the effect of familial environments and warrants attention. However, the concordant categories of mental disorders in couples remain unclear. This study investigated spousal concordance for the category of mental disorders among couples throughout Taiwan by using factors associated with such disorders.

METHODS

5643 couples in the 2002-2013 Taiwan National Health Insurance Research Database were analysed and compared with propensity-matched 5643 non-couples. Twelve independent variables, including spouse and shared characteristics, and the category of mental disorders were analysed, mainly by using multinomial logistic regression.

RESULTS

The determined prevalence rates for concordant categories of mental disorder were 0.19% for affective disorders, 6.96% for anxiety disorders, and 3.15% of other mental disorders. Multinomial logistic regression results revealed that two spouses were significantly more likely to be diagnosed with the same category of the aforementioned mental disorders (ORs=2.914, 1.776 and 1.727, respectively). Other associated factors included gender, age, occupation, comorbidity and region. The odds of concordances were significantly higher in couples than in non-couples.

CONCLUSIONS

A category of mental disorder in one spouse is a determinant of that in the other spouse. This study extended the emotional contagion theory to the phenomenon of parallel contagion to reflect the three concordances, suggesting a direction of family-based mental health intervention, particularly prevention for the same category of mental disorders in couples. Policymakers should strengthen the coping strategies of the caring spouse and external support system to psychiatrically vulnerable families.

The Occurrence and Traumatic Impact of Sexual Revictimization in Newlywed Couples

The present study examines whether individuals with a history of child sexual abuse are at risk of sexual revictimization in marriage and, if so, whether these experiences are associated with increased trauma symptomatology. Two hundred heterosexual newlywed couples were recruited from marriage license records and completed self-report assessments of past sexual victimization and sexual coercion within the marital dyad. Actor-Partner Interdependence Models revealed that, compared to non-victims, women with a history of child sexual abuse (CSA) experienced more acts of sexual coercion by their husbands during the past year. Moreover, there was a significant interaction between CSA and sexual coercion such that, among women who experienced CSA, the relationship between marital revictimization and trauma symptoms was stronger. Findings suggest that, for women but not men, sexual revictimization may occur in the context of a new marriage, and these experiences are associated with increased trauma symptoms. These findings have implications for understanding female survivors' perceptions of risk, and are particularly concerning given the high degree of personal and legal commitment involved in marriage.

Common Etiological Sources of Anxiety, Depression, and Somatic Complaints in Adolescents: A Multiple Rater twin Study

Somatic complaints in children and adolescents may be considered part of a broader spectrum of internalizing disorders that include anxiety and depression. Previous research on the topic has focused mainly on the relationship between anxiety and depression without investigating how common somatic symptoms relate to an underlying factor and its etiology. Based on the classical twin design with monozygotic and dizygotic twins reared together, our study aimed to explore the extent to which the covariation between three phenotypes in adolescent girls and boys can be represented by a latent internalizing factor, with a focus on both common and specific etiological sources. A population-based sample of twins aged 12-18 years and their mothers and fathers (N = 1394 families) responded to questionnaire items measuring the three phenotypes. Informants' ratings were collapsed using full information maximum likelihood estimated factor scores. Multivariate genetic analyses were conducted to examine the etiological structure of concurrent symptoms. The best fitting model was an ACE common pathway model without sex limitation and with one substantially heritable (44%) latent factor shared by the phenotypes. Concurrent symptoms also resulted from shared (25%) and non-shared (31%) environments. The factor loaded most on depression symptoms and least on somatic complaints. Trait-specific influences explained 44% of depression variance, 59% of anxiety variance, and 65% of somatic variance. Our results suggest the presence of a general internalizing factor along which somatic complaints and mental distress can be modeled. However, specific influences make the symptom types distinguishable.

Sex differences in genetic and environmental contributions to alcohol consumption from early adolescence to young adulthood

AIMS

To estimate genetic and environmental contributions to alcohol consumption from early adolescence to young adulthood, and test whether gender moderates these effects.

DESIGN

Longitudinal twin cohort design.

SETTING

Population-based sample from Norway.

PARTICIPANTS

A total of 2862 male and female twins, aged 14-22 years, were assessed at one (n = 881), two (n = 898) or three (n = 1083) occasions. The percentage of females was between 56 and 63 in the different age groups (in the different waves).

MEASUREMENTS

Alcohol consumption was measured by two questionnaire items about frequency of alcohol use and frequency of being drunk.

FINDINGS

Additive genetic effects showed low to moderate contributions [proportion estimate, 95% confidence interval (CI) = range from 0.03 (0.00-0.14) to 0.49 (0.37-0.59) in males and from 0.09 (0.00-0.57) to 0.41 (0.24-0.58) in females] from adolescence to young adulthood, while environmental influences shared by twin pairs and contributing to twin similarity were moderate to highly influential during this developmental period [proportion estimate, 95% CI = range from 0.04 (0.00-0.13) to 0.45 (0.26-0.60) in males for shared environment in common with females, from 0.25 (0.09-0.42) to 0.54 (0.06-0.78) for shared environment specific to males and from 0.36 (0.20-0.52) to 0.51 (0.37-0.71) in females]. There was evidence of qualitative sex differences with shared environmental influences being largely sex-specific from middle adolescence onwards.

CONCLUSIONS

Alcohol consumption from early adolescence to young adulthood appears to be influenced to a small to moderate degree by genetic factors and to a moderate to high degree by shared environmental factors (e.g. rearing influences, shared friends). The shared environmental factors influencing alcohol consumption appear to be largely gender-specific.

Symptoms of autism spectrum disorder and anxiety: shared familial transmission and cross-assortative mating

BACKGROUND

In order to shed more light on the frequent co-occurrence of Autism Spectrum Disorder (ASD) and anxiety in children, the aims of the study were (a) to examine whether ASD and anxiety share familial transmission indicated by cross-symptom associations between parental and children's symptoms (e.g., parental anxiety predicting children's ASD) in addition to associations for similar symptoms; (b) to investigate the possibility that cross-assortative mating (i.e., whether ASD symptoms in one parent are positively associated with anxiety symptoms in the other parent) increases the risk for both ASD and anxiety in children.

METHOD

In 231 families of clinically referred children, parents rated both their own and the other parent's ASD and anxiety symptoms and one parent those of the index child and siblings (n = 447, aged 2.5-18 years). ASD symptoms were assessed using the Social Responsiveness Scale (SRS-2) and anxiety symptoms using the Achenbach System of Empirically Based Assessment (ASEBA) instruments.

RESULTS

Parental ASD and anxiety symptoms predicted similar symptoms in children, dependent on the informant type. Additionally, parental anxiety symptoms across both self-report and informant-report predicted children's ASD symptoms and maternal self-reported ASD symptoms predicted children's anxiety symptoms. ASD and anxiety symptoms were correlated within parents, but we found only one cross-symptom association between parents.

CONCLUSIONS

Cross-symptom associations between parental and children's ASD and anxiety symptoms suggest shared familial transmission of ASD and anxiety, but further research is needed to clarify the underlying mechanisms. Cross-assortative mating does not seem a likely explanation for the co-occurrence of ASD and anxiety in children.

Examining the validity of the adapted Alabama Parenting Questionnaire-Parent Global Report Version

The purpose of the present study was to comprehensively examine the validity of an adapted version of the parent global report form of the Alabama Parenting Questionnaire (APQ) with respect to its factor structure, relationships with demographic and response style covariates, and differential item functioning (DIF). The APQ was adapted by omitting the corporal punishment and the other discipline items. The sample consisted of 674 Canadian and United States families having a 9- to 12-year-old child and at least 1 parent figure who had received treatment within the past 5 years for alcohol problems or met criteria for alcohol abuse or dependence. The primary parent in each family completed the APQ. The 4-factor CFA model of the 4 published scales used and the 3-factor CFA model of those scales from prior research were rejected. Exploratory structural equation modeling was then used. The final 3-factor model combined the author-defined Involvement and Positive Parenting scales and retained the original Poor Monitoring/Supervision and Inconsistent Discipline scales. However, there were substantial numbers of moderate magnitude cross-loadings and large magnitude residual covariances. Differential item functioning (DIF) was observed for a number of APQ items. Controlling for DIF, response style and demographic variables were related significantly to the factors. (PsycINFO Database Record

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.

Spousal resemblance in psychopathology: A comparison of parents of children with and without psychopathology

BACKGROUND

Spouses resemble each other for psychopathology, but data regarding spousal resemblance in externalizing psychopathology, and data regarding spousal resemblance across different syndromes (e.g. anxiety in wives and attention deficit/hyperactivity disorder [ADHD] in husbands) are limited. Moreover, knowledge is lacking regarding spousal resemblance in parents of children with psychiatric disorders. We investigated and compared spousal resemblance within and across internalizing and externalizing symptom domains in parents of children with and without psychopathology.

METHODS

Symptoms of depression, anxiety, avoidant personality, ADHD, and antisocial personality were assessed with the Adult Self Report in 728 mothers and 544 fathers of 778 children seen in child and adolescent psychiatric outpatient clinics and in 2075 mothers and 1623 fathers of 2784 children from a population-based sample. Differences in symptom scores and spousal correlations between the samples were tested.

RESULTS

Parents in the clinical sample had higher symptom scores than in the population-based sample. In both samples, correlations within and across internalizing and externalizing domains of psychopathology were significant. Importantly, correlations were significantly higher in the clinical sample (P=0.03). Correlations, within and across symptoms, ranged from 0.14 to 0.30 in the clinical sample and from 0.05 to 0.23 in the population-based sample.

CONCLUSIONS

This large study shows that spousal resemblance is not only present within but also across symptom domains. Especially in the clinical sample, ADHD symptoms in fathers and antisocial personality symptoms in mothers were correlated with a range of psychiatric symptoms in their spouses. Clinicians need to be alert of these multiple affected families.

Sex Differences in Sources of Resilience and Vulnerability to Risk for Delinquency

Research on adolescent risk factors for delinquency has suggested that, due to genetic differences, youth may respond differently to risk factors, with some youth displaying resilience and others a heightened vulnerability. Using a behavioral genetic design and data from the National Longitudinal Study of Adolescent to Adult Health, this study examines whether there are sex differences in the genetic and environmental factors that influence the ways in which adolescents respond to cumulative risk for violent, nonviolent, and overall delinquency in a sample of twins (152 MZ male, 155 MZ female, 140 DZ male, 130 DZ female, and 204 DZ opposite-sex twin pairs). The results revealed that males tended to show greater vulnerability to risk for all types of delinquency, and females exhibited greater resilience. Among males, additive genetic factors accounted for 41, 29, and 43 % of the variance in responses to risk for violent, nonviolent, and overall delinquency, respectively. The remaining proportion of variance in each model was attributed to unique environmental influences, with the exception of 11 % of the variance in nonviolent responses to risk being attributed to common environmental factors. Among females, no significant genetic influences were observed; however, common environmental contributions to differences in the ways females respond to risk for violent, nonviolent, and overall delinquency were 44, 42, and 45 %, respectively. The remaining variance was attributed to unique environmental influences. Overall, genetic factors moderately influenced males' responses to risk while environmental factors fully explain variation in females' responses to risk. The implications of these findings are discussed in the context of improving the understanding of relationships between risks and outcomes, as well as informing policy and practice with adolescent offenders.

Population-based, multi-generational family clustering study of social anxiety disorder and avoidant personality disorder

BACKGROUND

We aimed to provide unbiased estimates of familial risk and heritability of social anxiety disorder (SAD) and avoidant personality disorder (AVPD).

METHOD

We identified 18 399 individuals diagnosed with SAD and 2673 with AVPD in the Swedish National Patient Register between 1997 and 2009. Risks (odds ratios; OR) for SAD in all biological and non-biological relatives of probands, compared to relatives of unaffected individuals were calculated. We also estimated the risks for AVPD in relatives of probands with SAD.

RESULTS

The risk for SAD among relatives of SAD probands increased proportionally to the degree of genetic relatedness. The risks for first-degree relatives [OR 4.74, 95% confidence interval (CI) 4.28-5.25] were significantly higher than for second-degree and third-degree relatives. Second-degree relatives (OR 2.30, 95% CI 2.01-2.63) had significantly higher risk than third-degree relatives (OR 1.72, 95% CI 1.52-1.94). Relatives at similar genetic distances had similar risks for SAD, despite different degrees of shared environment. Heritability was estimated to be approximately 56%. There were no significant sex differences in the familial patterns. The risk of AVPD in relatives of SAD probands was significantly elevated, even after excluding individuals with both diagnoses (first-degree OR 3.54, second-degree OR 2.20, third-degree OR 1.62). Non-biological relatives (spouses/partners) also had elevated risks for both SAD (OR 4.01) and AVPD (OR 3.85).

CONCLUSIONS

SAD clusters in families primarily due to genetic factors. SAD and AVPD are aetiologically related and may represent different expressions of the same vulnerability. The strong marital concordance observed in SAD/AVPD may indicate assortative mating but the exact mechanisms and implications require further investigation.

The heritability of alcohol use disorders: a meta-analysis of twin and adoption studies

BACKGROUND

To clarify the role of genetic and environmental risk factors in alcohol use disorders (AUDs), we performed a meta-analysis of twin and adoption studies and explored the impact of sex, assessment method (interview v. hospital/population records), and study design (twin v. adoption study) on heritability estimates.

METHOD

The literature was searched for all unique twin and adoption studies of AUD and identified 12 twin and five adoption studies. The data were then reconstructed and analyzed using ordinal data full information maximum likelihood in the OpenMx program. Heterogeneity was tested with likelihood ratio tests by equating the parameters across studies.

RESULTS

There was no evidence for heterogeneity by study design, sex or assessment method. The best-fit estimate of the heritability of AUD was 0.49 [95% confidence interval (CI) 0.43-0.53], and the proportion of shared environmental variance was 0.10 (95% CI 0.03-0.16). Estimates of unique environmental proportions of variance differed significantly across studies.

CONCLUSIONS

AUD is approximately 50% heritable. The multiple genetically informative studies of this syndrome have produced consistent results that support the validity of this heritability estimate, especially given the different potential methodological weaknesses of twin and adoption designs, and of assessments of AUD based on personal interviews v. official records. We also found evidence for modest shared environmental effects suggesting that environmental factors also contribute to the familial aggregation of AUDs.

Divorce and subsequent increase in uptake of antidepressant medication: a Finnish registry-based study on couple versus individual effects

Background

There is an average negative mental health effect for individuals who experience divorce. Little is known whether the pattern of such divorce effects varies within couples. We study whether the husband and wife experience similar harmful effects of divorce, whether they experience opposite effects, or whether divorce effects are purely individual.

Methods

We use Finnish registry data to compare changes over a period of 5 years in antidepressant use of husbands and wives from 4,558 divorcing couples to 108,637 continuously married pairs aged 40–64, all of whom were healthy at baseline.

Results

In the period three years before and after divorce antidepressant use increases substantially. However, the likelihood of uptake of antidepressant medication during this process of divorce by one partner appears to be independent of medication uptake in the other partner. In contrast, among continuously married couples there is a clear pattern of convergence: If one partner starts to use antidepressants this increases the likelihood of uptake of antidepressant medication in the other partner.

Conclusions

Our findings suggest that divorce effects on antidepressant use are individual and show no pattern of either convergence or divergence at the level of the couple. The increased incidence of antidepressant use associated with divorce occurs in individuals independent of what happens to their ex-partner.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1508-9) contains supplementary material, which is available to authorized users.

Behavior problems and timing of menarche: a developmental longitudinal biometrical analysis using the NLSY-Children data

A powerful longitudinal data source, the National Longitudinal Survey of Youth Children data, allows measurement of behavior problems (BP) within a developmental perspective linking them to menarcheal timing (MT). In a preliminary analysis, we evaluate the bivariate relationships between BP measured at different developmental periods and the timing of menarche. Correlations were not consistent with any correlational/causal relationship between BP and MT. In the major part of our study, MT was used to moderate the developmental trajectory of BP, within a genetically-informed design. Girls reaching menarche early had behavior problem variance accounted for by the shared environment; those reaching menarche with average/late timing had behavior problem differences accounted for by genetic variance. Our findings match previous empirical results in important ways, and also extend those results. A theoretical interpretation is offered in relation to a theory linking genetic/shared environmental variance to flexibility and choices available within the family in relation to BP.

Genetic and environmental causes of variation in adolescent anxiety symptoms: a multiple-rater twin study

Heritability estimates for adolescent anxiety vary across studies, partly depending on who is rating the symptoms. The goal of our study was to estimate genetic and environmental influences using a multi-informant design with responses from a population-based sample of adolescent twins, their mothers and their fathers (N=1394 families). Results from multivariate biometrical modeling indicated quantitative, but no qualitative sex differences in etiology. The best fitting model was an AE Common Pathway model, defining anxiety as a latent factor common to all informants. This model offers error free estimates of genetic and environmental influences explaining the latent factor variance. Variation in the latent factor was highly genetic, with heritability estimates of 65% for boys and 74% for girls. Non-shared environmental effects explained the remaining variance. In addition, there were significant rater-specific genetic and environmental effects for both sexes. The observed rater differences underline the importance of using several informants when studying adolescent anxiety.

Risk of mental illness in offspring of parents with schizophrenia, bipolar disorder, and major depressive disorder: a meta-analysis of family high-risk studies

OBJECTIVE

Offspring of parents with severe mental illness (SMI; schizophrenia, bipolar disorder, major depressive disorder) are at an increased risk of developing mental illness. We aimed to quantify the risk of mental disorders in offspring and determine whether increased risk extends beyond the disorder present in the parent.

METHOD

Meta-analyses of absolute and relative rates of mental disorders in offspring of parents with schizophrenia, bipolar disorder, or depression in family high-risk studies published by December 2012.

RESULTS

We included 33 studies with 3863 offspring of parents with SMI and 3158 control offspring. Offspring of parents with SMI had a 32% probability of developing SMI (95% CI: 24%-42%) by adulthood (age >20). This risk was more than twice that of control offspring (risk ratio [RR] 2.52; 95% CI 2.08-3.06, P < .001). High-risk offspring had a significantly increased rate of the disorder present in the parent (RR = 3.59; 95% CI: 2.57-5.02, P < .001) and of other types of SMI (RR = 1.92; 95% CI: 1.48-2.49, P < .001). The risk of mood disorders was significantly increased among offspring of parents with schizophrenia (RR = 1.62; 95% CI: 1.02-2.58; P = .042). The risk of schizophrenia was significantly increased in offspring of parents with bipolar disorder (RR = 6.42; 95% CI: 2.20-18.78, P < .001) but not among offspring of parents with depression (RR = 1.71; 95% CI: 0.19-15.16, P = .631).

CONCLUSIONS

Offspring of parents with SMI are at increased risk for a range of psychiatric disorders and one third of them may develop a SMI by early adulthood.

Bad, burdened or ill? Characterizing the spouses of women with schizophrenia

BACKGROUND

The husbands of women with schizophrenia have been variously characterized in the psychiatric literature as abusive, burdened and ill. The aim of this paper is to summarize what has been written about these three perspectives.

METHOD

The search terms 'schizophrenia', 'mental illness', 'marriage', 'spouse', 'partner', 'caregiver', 'caregiving', 'burden', 'assortative mating' and 'domestic abuse' were entered into PubMed and Google Scholar. Criteria for inclusion of articles were relevance to the three identified themes of abuse, burden and mental illness in husbands of women with schizophrenia. The results show considerable variation, some of it cultural, with partial evidence for all three characterizations.

CONCLUSION

There is a need for support and psychoeducation programmes that are specifically designated for spouses and that address their special concerns.

The role of parent psychopathology in the development of preschool children with behavior problems

The present study examined associations between early parental self-reported psychopathology symptoms and the later behavioral, emotional, and social functioning of preschool children with behavior problems. Mothers and fathers of preschoolers with behavior problems (N = 132; 55 girls, 77 boys) completed parent psychopathology questionnaires when children were 3 years old and completed measures of children's externalizing, internalizing, and social problems annually from age 3 to age 6. The sample included 61% European American, 16% Latino (predominantly Puerto Rican), 10% African American, and 13% multiethnic children. Every dimension of mothers' and fathers' psychopathology symptoms when children were 3 years old was associated with their own reports of children's externalizing and internalizing problems 3 years later. Several dimensions of maternal psychopathology symptoms at age 3 were associated with mother-reported social skills 3 years later. However, the relation between many dimensions of psychopathology symptoms and child outcome appears to be accounted for by co-occurring psychopathology symptoms. Only maternal attention-deficit hyperactivity disorder (ADHD) and Cluster A symptoms, and paternal ADHD and depression/anxiety symptoms emerged as unique predictors of child functioning. These findings suggest that most types of mothers' and fathers' self-reported psychopathology symptoms may play a role in the prognosis of behavioral, social, and emotional outcomes of preschoolers with behavior problems, but that co-occurring symptoms need to be considered.