The current study examined longitudinal associations between friend’s substance use, friendship quality, parent-adolescent relationship quality and subsequent substance use. Participants were 166 adolescents, their parents and their close same-sex friends. Measures of relationship characteristics in the 10th grade were used to predict concurrent substance use and changes in substance use over a one-year period. The most consistent predictor of the use of different substances and changes in substance use over time was the friend’s substance using behavior. Negative interactions with a friend were related only to tobacco use, and friendship support neither contributed to nor protected against substance use. Mother-adolescent relationship support was associated with lower levels of concurrent substance use, as well as lower levels of hard drug use over time. Findings highlight the need to examine parents and peers simultaneously and the importance of parental relationships and peer behavior on adolescent substance use. Limitations and future directions are discussed.

OBJECTIVE: To understand the influence of physical activity on teen smoking-cessation outcomes. METHODS: Teens (N = 233; 14–19 years of age) from West Virginia high schools who smoked >1 cigarette in the previous 30 days were included. High schools with >300 students were selected randomly and assigned to brief intervention (BI), Not on Tobacco (N-O-T) (a proven teen cessation program), or N-O-T plus a physical activity module (N-O-T+FIT). Quit rates were determined 3 and 6 months after baseline by using self-classified and 7-day point prevalence quit rates, and carbon monoxide validation was obtained at the 3-month follow-up evaluation. RESULTS: Trends for observed and imputed self-classified and 7-day point prevalence rates indicated that teens in the N-O-T+FIT group had significantly higher cessation rates compared with those in the N-O-T and BI groups. Effect sizes were large. Overall, girls quit more successfully with N-O-T compared with BI (relative risk [RR]: >∞) 3 months after baseline, and boys responded better to N-O-T+FIT than to BI (RR: 2–3) or to N-O-T (RR: 1–2). Youths in the N-O-T+FIT group, compared with those in the N-O-T group, had greater likelihood of cessation (RR: 1.48) at 6 months. The control group included an unusually large proportion of participants in the precontemplation stage at enrollment, but there were no significant differences in outcomes between BI and N-O-T (z = 0.94; P = .17) or N-O-T+FIT (z = 1.12; P = .13) participants in the precontemplation stage. CONCLUSIONS: Adding physical activity to N-O-T may enhance cessation success, particularly among boys.

When adolescents begin using substances, negative consequences are not always directly proportional to the amount used; heavy users may have few consequences whereas light users may have numerous consequences. This study examined how parental monitoring knowledge and parent-child relationship quality may serve as buffers against negative consequences when adolescents use substances. Self-report questionnaires were administered to a community sample of 200 healthy adolescents and their parents at two time points, one year apart. Results suggest that both parental monitoring knowledge and parent-child relationship quality serve as buffers against negative consequences of substance use – but only when adolescents report high levels of monitoring knowledge or strong parent-child relationship quality. Results suggests adolescent perceived parental monitoring knowledge and parent-child relationship quality each act independently to buffer adolescents against negative consequences of substance use over a one-year period.