A test of socioeconomic status as a predictor of initial marijuana use

The current study examined the effects of socioeconomic status (SES) on adolescent marijuana use using data from a national longitudinal survey of subjects aged 11 to 17 (N = 1,725). Both direct and indirect measures of SES (e.g., Hollingshead's measure of SES, predicts marijuana use among adolescents. For males, our study found a nonlinear relationship between the Hollingshead measure and marijuana use that had not been identified in previous research. For females, the Hollingshead measure was nonsignificant when alcohol use and having friends who use marijuana were added to the model. This finding suggests that the effects of SES on marijuana use may be mediated by alcohol use and friends' use of marijuana. Weekly alcohol users were much more likely than nonusers to initiate marijuana use for both males (Odds ratio [OR] = 18.28, Confidence interval [CI] = 4.93-67.81) and females (OR = 11.75, CI = 3.22-42.86). Other significant variables for both sexes included having a job, having friends who use marijuana, and having used some alcohol in the past year. For males, grade point average (GPA), commitment to friends, urbanicity, time spent with friends, and peer strain were also significant predictors of initial marijuana use. For females, prior victimization and low school aspirations were significant. In sum, our findings suggest that psychosocial risk factors for marijuana use are substantially different for males than for females and that future researchers need to test for nonlinear relationships between SES and adolescent substance use.