Developmental trajectories of substance use from early adolescence to young adulthood: gender and racial/ethnic differences.

PURPOSE: The current study examined gender and racial/ethnic (Hispanics, non-Hispanic Caucasians, non-Hispanic African Americans, and non-Hispanic Asians) differences in developmental trajectories of alcohol use, heavy drinking, smoking, and marijuana use from early adolescence to young adulthood using a nationally representative sample.
METHODS: Participants from the National Longitudinal Study of Adolescent Health (N = 20,160) reported rates of alcohol use, heavy drinking, smoking, and marijuana use between the ages of 12 and 34 years. Data analyses were completed using longitudinal multilevel modeling analyses.
RESULTS: Levels of substance use increased from early adolescence to mid-20s, and then declined thereafter. Females showed higher levels of substance use in early adolescence, although males exhibited greater changes overtime and higher levels of use in mid-adolescence and early adulthood. Overall, Hispanic youth had higher initial rates of substance use, whereas Caucasian adolescents showed higher rates of change and had the highest levels of substance use from mid-adolescence through the early 30s. Racial/ethnic differences largely disappeared after age 30, except that African Americans showed higher final levels of smoking and marijuana use than the other racial/ethnic groups. Results provide evidence for both similarities and differences in general patterns of development and in gender and racial/ethnic differences across different forms of substance use.
CONCLUSIONS: Findings from the current study suggest that the critical periods for intervention and prevention of substance use may differ across gender and race/ethnicity, and that future research needs to identify common and unique mechanisms underlying developmental patterns of different forms of substance use.