Abstract

Background: Existing research on adolescent drug use lacks cultural diversity and compare users/non-users, but not between users with/without dependence. The research aims were to examine whether (1) family and peer marijuana use are independently related to adolescent marijuana use in Chile, (2) family and peer use are associated with adolescent dependence in adolescents using marijuana, and (3) the adolescent’s age moderates the association between family or peer use and adolescent use and dependence. Methods: It was conducted a cross-sectional study using regression analyses based on the Chilean National Survey on Drug Use. It was included 4,413 adolescents, aged 12-19 (surveys 2008 and 2010). It was measured the association between adolescent marijuana use and dependence (ICD-10 criteria), family and peer marijuana use, and the interaction of an adolescent’s age with family and peer marijuana use. Findings: Adolescents who have someone at home using marijuana were five times more likely to use the drug (p< .001); meanwhile, adolescents with a close friend who used marijuana were eight times more likely to do so (p< .001). When adolescents were using marijuana, they were three times more likely to present a dependence (p= .015), if they had a family member using the drug. However, no significant relationship was found for peer use (p= .683). No statistical interactions between family or peer use and age were found. Discussion: Family and peer marijuana use were independently associated with adolescent past-year marijuana use, but only family marijuana use was statistically associated with adolescent marijuana dependence.