Friend support and psychological distress in a U.S. adult twin sample

Friend support is often assumed to exert direct environmental influences on psychological distress, yet the role of both genetic and environmental influences on this association has not been examined. This study investigates whether both genetic and environmental factors explain the link between friend support and psychological distress in adults. The sample was drawn from the Midlife Development in the United States study and included 947 pairs of monozygotic, same‐sex dizygotic (DZ), and opposite‐sex DZ twins. Results showed that genetic influences explain the association between friend support and psychological distress, suggesting that heritable contributions to friend support also shape psychological distress. Interventions focused on psychological distress should consider how individuals' heritable characteristics influence their friend support and psychological distress.     

Individual Resiliency Factors from a Genetic Perspective: Results from a Twin Study

This article is part of the Twin Mother's Study, a study that examines influences on maternal adjustment. A number of studies have investigated the importance of genetic factors for mental health, but few of these examine how genes and the environment influence resiliency/salutogenic factors. This article investigates the relative importance of genetic and environmental influences on resiliency/salutogenic factors. This study includes 326 twin pairs (150 monozygotic and 176 dizygotic) who are mothers, who are living with their spouse, and who are part of the Swedish twin register. Using self‐report structured questionnaires, we assessed salutogenic factors, depression, and quality of life; however, we analyzed the questionnaires completed by the mothers. Statistical analyses were conducted using structural equation modeling. We conclude that nonshared environmental components were of principal importance in individual resiliency/salutogenic factors in a genetically informative design, but we also noted that genetic influences were important. The shared environment had mainly no effect.