The contribution of peers to monthly variation in adolescent depressed mood: a short-term longitudinal study with time-varying predictors.

This study examined peer predictors of variation and growth in depressed mood among high-risk adolescents, using child and parent reports of monthly symptoms. One hundred seventy-six parents and their 10- to 14-year-old children separately took part in a series of up to nine monthly interviews. Multilevel growth models examined both time-varying peer predictors of parent and child reports of the child's depressive symptoms, controlling for age, gender, and treatment status. Deviant peer affiliation significantly predicted elevated depressive symptoms in the monthly child-report of depressed mood, especially for younger adolescents. Children's level of delinquency was significantly related to parent-reported depressive symptoms, and to child-reported symptoms in older adolescents only. As expected, depressed mood was higher for girls and more prevalent among older adolescents. The results suggest that peer processes may be linked in time to the development of depression, especially among high-risk adolescents.