Genetic and environmental influences on rumination, distraction, and depressed mood in adolescence

Rumination is an established cognitive vulnerability for depression. Despite substantial work on the environmental origins of rumination, the heritability of rumination has not been examined, and it is not known whether rumination accounts for some of the genetic vulnerability associated with depression. A total of 756 adolescent twins aged 12 to 14 years completed the Response Styles Questionnaire and multiple measures of depressive symptoms. Brooding correlated positively, and distraction negatively, with concurrent depressive symptoms. Estimated heritabilities were 54% for depression, 21% for brooding, 37% for reflection, and 30% for distraction. Bivariate genetic analyses suggested that (a) individual differences in distraction share both genetic and environmental sources of variation with depression and (b) although the heritable influences on brooding are small, they account for the majority of the relationship between brooding and depression (h² =.62).