BACKGROUND: This study examined how interpersonal relationships, specifically marital quality and adequacy of social support, are associated with depressive symptoms among women. METHODS: A sample of 326 female monozygotic and dizygotic twin pairs and their spouses was drawn from the Swedish Twin Registry. Associations among the three variables were evaluated by comparing similarities among monozygotic and dizygotic female twin pairs. RESULTS: Interpersonal relationships contributed between 18% and 31% of the variance for depressive symptoms in women. Associations among the three variables were accounted for by genetic influences when women's reports were used. Non-shared environmental influences were important for the association between marital quality and depressive symptoms when a combination of husband and wife reports of marital quality were used. LIMITATIONS: The data is cross-sectional and the generalizability of these findings to depressive symptoms in men or to individuals with major depression is not clear. CONCLUSIONS: These findings indicate important associations among marital quality, social support and depressive symptoms in women, which should be taken into consideration for prevention and intervention strategies targeting depression.
We examined how genotype-environment correlation processes differ as a function of adolescent age. We tested whether adolescent age moderates genetic and environmental influences on positivity and negativity in mother-adolescent and father-adolescent relationships using parallel samples of twin parents from the Twin and Offspring Study in Sweden and twin/sibling adolescents from the Nonshared Environment in Adolescent Development Study. We inferred differences in the role of passive and nonpassive genotype-environment correlation based on biometric moderation findings. The findings indicated that nonpassive gene-environment correlation played a stronger role for positivity in mother- and father-adolescent relationships in families with older adolescents than in families with younger adolescents, and that passive gene-environment correlation played a stronger role for positivity in the mother-adolescent relationship in families with younger adolescents than in families with older adolescents. Implications of these findings for the timing and targeting of interventions on family relationships are discussed.
Low self-worth during adolescence predicts a range of emotional and behavioural problems. As such, identifying potential sources of influence on self-worth is important. Aspects of the parent-child relationship are often associated with adolescent self-worth but to date it is unclear whether such associations may be attributable to familial confounding (e.g. genetic relatedness). We set out to clarify the nature of relationships between parental expressed affection and adolescent self-worth, and parent-child closeness and adolescent self-worth.
We used data from the Twin and Offspring Study in Sweden, a children-of-twins sample comprising 909 adult twin pairs with adolescent children. Using these data we were able to apply structural equation models with which we could examine whether associations remained after accounting for genetic transmission.
Results demonstrated that parent-child closeness and parental-expressed affection were both phenotypically associated with adolescent self-worth. Associations could not be attributed to genetic relatedness between parent and child.
Parent-child closeness and parental affection are associated with adolescent self-worth above and beyond effects attributable to genetic relatedness. Data were cross-sectional, so the direction of effects cannot be confirmed but findings support the notion that positive parent-child relationships increase adolescent self-worth.
A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52 %) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression.
CONTEXT: The association between maternal smoking during pregnancy (SDP) and offspring disruptive behaviors has been well documented, but it is unclear whether exposure to SDP or the effects of factors correlated with SDP account for the increased risk. OBJECTIVE: To test whether the association between SDP and offspring criminal convictions was consistent with a causal connection or due to familial background factors by controlling for measured covariates and using a quasi-experimental approach. DESIGN: We used a population-based study of children born in Sweden from 1983 to 1989 (N = 609,372) to examine the association between SDP and offspring criminal convictions while controlling for measured traits of both parents. We also compared siblings differentially exposed to SDP (n = 50,339) to account for unmeasured familial factors that could account for the association. SETTING: Population-based study of all children born in Sweden from 1983 to 1989 with information on maternal SDP and offspring criminal convictions based on national registries collected by the Swedish government. PATIENTS OR OTHER PARTICIPANTS: Children born in Sweden from 1983 to 1989 (N = 609,372) and siblings differentially exposed to SDP (n = 50,339). MAIN OUTCOME MEASURES: Violent and nonviolent convictions, based on the Swedish National Crime Register, a register with detailed information on all convictions in the country. RESULTS: Moderate (hazard rate [HR], 2.47; 95% confidence interval [CI], 2.34-2.60) and high (HR, 3.43; 95% CI, 3.25-3.63) levels of maternal SDP were associated with an increased risk for offspring violent convictions, even when controlling for maternal and paternal traits. There was no association between SDP and violent convictions, however, when comparing differentially exposed siblings (HR(moderate), 1.02; 95% CI, 0.79-1.30; HR(high), 1.03; 95% CI, 0.78-1.37). Smoking during pregnancy also was associated with nonviolent convictions in the entire population (HR(moderate), 1.62; 95% CI, 1.58-1.66; HR(high), 1.87; 95% CI, 1.82-1.92) and when controlling for covariates. But, there was no association when comparing siblings who were differentially exposed (HR(moderate), 0.89; 95% CI, 0.78-1.01; HR(high), 0.89; 95% CI, 0.78-1.02). CONCLUSION: The results suggest that familial background factors account for the association between maternal SDP and criminal convictions, not the specific exposure to SDP.
Research has documented associations between family functioning and offspring psychosocial adjustment, but questions remain regarding whether these associations are partly due to confounding genetic factors and other environmental factors. The current study used a genetically informed approach, the Children of Twins design, to explore the associations between family functioning (family conflict, marital quality, and agreement about parenting) and offspring psychopathology. Participants were 867 twin pairs (388 monozygotic; 479 dizygotic) from the Twin and Offspring Study in Sweden, their spouses, and children (51.7% female; M = 15.75 years). The results suggested associations between exposure to family conflict (assessed by the mother, father, and child) and child adjustment were independent of genetic factors and other environmental factors. However, when family conflict was assessed using only children's reports, the results indicated that genetic factors also influenced these associations. In addition, the analyses indicated that exposure to low marital quality and agreement about parenting was associated with children's internalizing and externalizing problems and that genetic factors also contributed to the associations of marital quality and agreement about parenting with offspring externalizing problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
This study examined genetic and environmental influences on global family conflict. The sample comprised 872 same-sex pairs of twin parents, their spouses/partners, and one adolescent child per twin from the Twin and Offspring Study in Sweden. The twins, spouses, and child each reported on the degree of family conflict, and there was significant agreement among the family members' ratings. These shared perspectives were explained by one common factor, indexing global family conflict. Genetic influences explained 36% of the variance in this common factor, suggesting that twins' heritable characteristics contribute to family conflict, via genotype-environment correlation. Nonshared environmental effects explained the remaining 64% of this variance, indicating that twins' unique childhood and/or current family experiences also play an important role.
The literature consistently shows an association between pubertal maturation and internalizing problems in girls. The association for boys is less clear. The present study examines genetic and environmental influences on the association between pubertal maturation and internalizing problems for boys and girls in two primarily Caucasian adolescent twin/sibling studies: The Swedish Twin study of CHild and Adolescent Development (706 same-sex twin pairs aged 13-14, M = 13.7 years, 50 % female), and the Nonshared Environment in Adolescent Development sample (US-based, 687 same-sex twin/sibling pairs aged 10-18, M = 13.6 years, 47 % female). For girls, more advanced pubertal maturation was associated modestly with more internalizing problems, and that association was entirely explained by shared environmental influences. For boys, the association between pubertal maturation and internalizing problems was weak and inconsistent. Results for girls were remarkably consistent across samples. Findings suggest that nongenetic mechanisms mediate the association between pubertal maturation and internalizing problems. Findings have implications for intervention such that environmental influences shared by twins/siblings may provide the best targets for intervention strategies designed to minimize the potential negative effects of pubertal maturation on internalizing symptoms in girls.
Interpersonal relationships are important factors in mental health. A genetically sensitive design was used to examine associations among marital quality, adequacy of social support, and 2 aspects of positive mental health in a sample of 652 Swedish twin women and their families. There were 3 main findings. First, the covariance between relationships and positive mental health was partially accounted for by common genetic variance. Second, nonshared environmental influences played a substantial role in the covariance among the 3 constructs, with evidence for husbands being a source of this influence. Finally, different patterns of associations were found between relationships and 2 aspects of mental health, well-being and global self-worth, which shows how seemingly similar constructs can be differentially associated with relationships. Together, these findings emphasize the importance of genetically informed studies in family research and the role of the environment and interpersonal relationships in promoting and improving mental health.
The transmission of anxiety within families is well recognized, but the underlying processes are poorly understood. Twin studies of adolescent anxiety demonstrate both genetic and environmental influence, and multiple aspects of parenting are associated with offspring anxiety. To date, the children-of-twins design has not been used to evaluate the relative contributions of genetic transmission compared with direct transmission of anxiety from parents to their offspring.
Anxiety and neuroticism measures were completed by 385 monozygotic and 486 dizygotic same-sex twin families (37% male twin pair families) from the Twin and Offspring Study in Sweden. Structural equation models tested for the presence of both genetic and environmental transmission from one generation to the next.
For both anxiety and neuroticism, the models provide support for significant direct environmental transmission from parents to their adolescent offspring. In contrast, there was no evidence of significant genetic transmission.
The association between parental and offspring anxiety largely arises because of a direct association between parents and their children independent of genetic confounds. The lack of genetic transmission may reflect there being different genetic effects on these traits in adolescence and adulthood. Direct environmental transmission is in line with developmental theories of anxiety suggesting that children and adolescents learn anxious behaviors from their parents through a number of pathways such as modeling. Future analyses should combine children-of-twins data with child twin data in order to examine whether this direct effect solely represents parental influences on the offspring or whether it also includes child/adolescent anxiety evoking parental anxiety.
Comment In: Am J Psychiatry. 2015 Jul;172(7):597-826130196