Perspectives on adolescent substance use. A defined population study.

We asked 1447 tenth graders to complete a survey on physical activity, nutrition, stress, and substance use and to undergo basic physical assessments. In a multiple regression analysis, increased level of substance use by both boys and girls was most strongly predicted by friends' marijuana use. For boys, this was followed by perceived safety of cigarette smoking; poor school performance; parents' education; and use of diet pills, laxatives, or diuretics for weight control, accounting for 44% of the overall variation in substance use. For girls, friends' marijuana use was followed by poor school performance; self-induced vomiting for weight control; perceived safety of cigarette smoking; use of diet pills, laxatives, or diuretics for weight control; parents' education; perceived adult attitudes about cigarettes; and nonuse of seat belts, accounting for 53% of the overall variance. Separate multiple regression analyses for each substance produced similar results. The homogeneity of the study population precluded ethnic comparisons. These findings suggest that for many purposes substance use may be considered a single behavior regardless of the specific substance(s) used and that substance use may exist as part of a syndrome of adolescent problem behaviors. In addition, the potent influence of perceived social environment suggests that a social influence resistance model may represent the most successful preventive strategy.