This longitudinal study examined peer contagion of depressive symptoms over an 18-month interval within a sample of 100 11th-grade adolescents. Three types of peer contagion moderators were examined, including characteristics of adolescents (social anxiety, global self-worth), friends (level of friends' peer-perceived popularity), and the relationship between them (friendship quality). Measures were collected using adolescents' and their friends' reports of depressive symptoms, adolescents' reports of social anxiety, global self-worth, friendship quality, and a sociometric assessment of peer-perceived popularity. Results indicated that among girls higher levels of social anxiety were associated with adolescents' greater susceptibility to peer contagion. Among boys, higher levels of friends' peer perceived popularity and lower levels of positive friendship quality each were associated with greater susceptibility to depressive symptom contagion.