Ethnic differences in adolescent substance initiation sequences.

OBJECTIVES To evaluate ethnic differences in the initiation sequences of tobacco, alcohol, marijuana, and cocaine use among US high school students and to determine if ethnicity is a predictor of progression from licit to illicit substances or initiation of illicit substances before licit substances. DESIGN Cross-sectional analyses of the Centers for Disease Control and Prevention's 1995 Youth Risk Behavior Survey. SETTING US high schools. PARTICIPANTS A total of 8550 high school students randomly selected by cluster design. MAIN OUTCOME MEASURES Respondents were categorized based on self-reported sequence of initiating substances as follows: none, licit substances only, licit substances then illicit substances (typical), illicit substances first (reverse), and licit and illicit substances at the same time (concurrent). RESULTS Adjusting for age, maternal education, and region, progression from licit to illicit substances was significantly associated with black ethnicity (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.04-2.1) and male sex (OR, 1.4; 95% CI, 1.2-1.6). Black male and Latino female students whose mothers completed at least high school were more likely than white students with similarly educated mothers to initiate illicit substances before licit substances (OR, 3.0; 95% CI, 1.7-5.3; and OR, 5.9; 95% CI, 1.7-20; respectively). Similar trends were noted for the concurrent sequence. CONCLUSIONS The pattern of initiating tobacco, alcohol, marijuana, and cocaine use differs by ethnicity. Maternal education may be a proxy variable for other significant risk factors.