Is Depression Contagious? A Test of Alternative Peer Socialization Mechanisms of Depressive Symptoms in Adolescent Peer Networks

Purpose: This study examined the role of two different types of peer socialization (convergence, contagion) in adolescents' depression, adjusting for the effects of peer selection and deselection. Methods: The sample used in this study comprised 949 Finnish adolescents (56% females; mean age: 16 years at the outset) attending classrooms in eight secondary schools. Participants identified three school peers and reported depressive symptoms twice, 1 year apart. Sociometric and behavioral data were analyzed using dynamic social network analysis. Results: Adolescents initiated relationships with peers who reported similar levels of depression before initiation of the relationship, and dissolved relationships with peers who became dissimilar in depression from time 1 (T1) to time 2 (T2). The average score of peers' depressive symptoms at T1 predicted changes in adolescent depression at T2 (convergence), but adolescents with peers who reported relatively higher initial levels of depression did not report an increase in depression (contagion). Conclusions: Over time, adolescents' depressive symptoms increasingly converged toward the average levels of their peers, but this convergence was not primarily because of contagion effects. The findings suggest that socialization processes can lead to both increases and decreases in adolescent depression, depending on peers' average level of depression. (C) 2012 Society for Adolescent Health and Medicine. All rights reserved.