Changes in the strength of peer influence and cultural factors on substance use initiation between late adolescence and emerging adulthood in a Hispanic sample.

We examine whether peer substance use and cultural factors differentially influence the initiation of tobacco, alcohol, and marijuana use in adolescence and emerging adulthood (EA) among a community-based sample of Hispanics. Participants provided data in 11th grade (M = 16.8 years old, SD = 0.54) and emerging adulthood (M = 20.3 years old, SD = 0.6). Peer tobacco use had a stronger association with initiation of tobacco use in emerging adulthood (OR = 1.46, 95% CI = 1.13, 1.89) than in adolescence (OR = 1.20, 95% CI = 1.03, 1.40), but this pattern was not observed with initiation of alcohol or marijuana use. Cultural orientation is associated with initiation of tobacco use during EA but not with initiation of alcohol or marijuana use.