Adolescents' and their friends' health-risk behavior: factors that alter or add to peer influence.

OBJECTIVE: To examine models of risk for adolescent health-risk behavior, including family dysfunction, social acceptance, and depression as factors that may compound or mitigate the associations between adolescents' and peers' risk behavior.

METHODS: Participants were 527 adolescents in grades 9-12. Adolescents reported on their substance use (cigarette and marijuana use, heavy episodic drinking), violent behavior (weapon carrying, physical fighting), suicidality (suicidal ideation and attempts), and the health-risk behavior of their friends.

RESULTS: Adolescents' substance use, violence, and suicidal behavior were related to their friends' substance use, deviance, and suicidal behaviors, respectively. Friends' prosocial behavior was negatively associated with adolescent violence and substance use. Family dysfunction, social acceptance, and depression altered the magnitude of association between peers' and adolescents' risk behavior. In cumulative risk factor models, rates of adolescent health-risk behavior increased twofold with each added risk factor.

CONCLUSIONS: Results supported both additive and multiplicative models of risk. Implications for intervention and primary prevention are discussed.