Sex differences in adolescent depression: stress exposure and reactivity models. Child Dev 2007;78:279–95

Stress exposure and reactivity models were examined as explanations for why girls exhibit greater levels of depressive symptoms than boys. In a multiwave, longitudinal design, adolescents ’ depressive symptoms, al-cohol usage, and occurrence of stressors were assessed at baseline, 6, and 12 months later (N5 538; 54.5% female; ages 13 – 18, average 14.9). Daily stressors were coded into developmentally salient domains using a modified contextual-threat approach. Girls reported more depressive symptoms and stressors in certain con-texts (e.g., interpersonal) than boys. Sex differences in depression were partially explained by girls reporting more stressors, especially peer events. The longitudinal direction of effects between depression and stressors varied depending on the stressor domain. Girls reacted more strongly to stressors in the form of depression. Adolescence has been characterized as a hallmark period of transition with numerous biological, social, and psychological challenges. Such difficulties fre-quently persist into adulthood and may have impor-tant long-term implications that forecast continued problems with physical and mental health and devel-opment. A considerable amount of theory and research points to enhanced difficulties for girls as they enter adolescence (Crick & Zahn-Waxler, 2003). Indeed, girls begin to exhibit more internalizing emotional problems, especially symptoms of depression, than boys starting in early adolescence and lasting throughout most of adulthood (Hankin & Abramson, 1999; Kuehner, 2003). However, despite this well-replicated finding, com-paratively less research has explained the sex difference in depression during adolescence. As such, the primary purpose of the present study was to use data from a multiwave prospective study to test developmentally based explanations for why more girls than boys ex-perience depression starting in adolescence. We exam-ined both mediational and moderational models of how the frequency and type of stressors experienced by girls and boys predict depression. Descriptive Timeline for the Development of the Se