Gene-environment interplay in internalizing disorders: consistent findings across six environmental risk factors.

BACKGROUND: Behavior genetic methods can help to elucidate gene-environment (G-E) interplay in the development of internalizing (INT) disorders (i.e., major depression and anxiety disorders). To date, however, no study has conducted a comprehensive analysis examining multiple environmental risk factors with the purpose of delineating general mechanisms of G-E influence in the development of INT disorders. METHODS: The sample consisted of 1315 male and female twin pairs participating in the age 17 assessment of the Minnesota Twin Family Study. Quantitative G-E interplay models were used to examine how genetic and environmental risk for INT disorders changes as a function of environmental context. Multiple measures and informants were employed to construct composite measures of INT disorders and six environmental risk factors including: stressful life events, mother-child and father-child relationship problems, antisocial and prosocial peer affiliation, and academic achievement and engagement. RESULTS: Significant moderation effects were detected between each environmental risk factor and INT such that in the context of greater environmental adversity, nonshared environmental factors became more important in the etiology of INT symptoms. CONCLUSION: Our results are consistent with the interpretation that environmental stressors have a causative effect on the emergence of INT disorders. The consistency of our results suggests a general mechanism of environmental influence on INT disorders regardless of the specific form of environmental risk.

Environmental adversity and increasing genetic risk for externalizing disorders.

CONTEXT: Studies of gene-environment interplay in the development of psychiatric and substance use disorders are rapidly accumulating. However, few attempts have been made to integrate findings and to articulate general mechanisms of gene-environment influence in the emergence of psychopathology. OBJECTIVE: To identify patterns of gene-environment interplay between externalizing disorders (antisocial behavior and substance use) and several environmental risk factors. DESIGN: We used quantitative genetic models to examine how genetic and environmental risk for externalizing disorders changes as a function of environmental context. SETTING: Participants were recruited from the community and took part in a daylong assessment at a university laboratory. PARTICIPANTS: The sample consisted of 1315 male and female twin pairs participating in the assessment of the Minnesota Twin Family Study at age 17 years. MAIN OUTCOME MEASURES: Multiple measures and informants were used to construct a composite of externalizing disorders and composite measures of 6 environmental risk factors, including academic achievement and engagement, antisocial and prosocial peer affiliations, mother-child and father-child relationship problems, and stressful life events. RESULTS: A significant gene x environment interaction was detected between each environmental risk factor and externalizing such that greater environmental adversity was associated with increased genetic risk for externalizing. CONCLUSIONS: In the context of environmental adversity, genetic factors become more important in the etiology of externalizing disorders. The consistency of the results further suggests a general mechanism of environmental influence on externalizing disorders regardless of the specific form of the environmental risk.

Natural history of male psychological health, XV: retirement satisfaction.

OBJECTIVE: Although previous studies of shorter duration have identified numerous risks and protective factors that powerfully influence outcomes in young adulthood and midlife, this long-term prospective study examines the effect of these prognostic factors on age at retirement and satisfaction with retirement. METHOD: In this prospective study, a cohort of socially disadvantaged men (N=151) were followed from adolescence until a mean age of 75 years (SD=2). Periodic interviews, biennial administration of questionnaires, and physical examinations every 5 years were conducted to determine biopsychosocial risk variables, age at retirement, and satisfaction with retirement. RESULTS: Early age of retirement was found to be a function of preexisting mental and physical health and later age of retirement a function of occupational status. A surprising finding was that risk factors such as poor objective physical health, low income, and depression, which are commonly associated with poor outcomes in young adulthood and in midlife, were largely unrelated to satisfaction with retirement. CONCLUSIONS: A relatively high level of satisfaction with retirement was often attained by men who had reported many risk factors for poor child and midlife development (e.g., low IQ, dropping out of school, poor mental health, and being part of a multiproblem family) but who in later life had some positive resources (e.g., a good marriage, a low level neuroticism, enjoyment of vacations, and a capacity for play). In short, retirement may offer some men a fresh lease on life.