Substance Use Trajectories from Early Adolescence to Emerging Adulthood

Over the past several years, there has been growing interest in identifying distinct developmental trajectories of substance use. Using data from the RAND Adolescent/ Young Adult Panel Study (N = 6,527), the authors synthesize our prior findings on patterns of smoking, binge drinking, and marijuana use from early adolescence (age 13) to emerging adulthood (age 23). The authors also present new data on how these trajectory classes compare on key psychosocial and behavioral outcomes during emerging adulthood. For each type of substance use, the authors found two periods of vulnerability: early adolescence and the transition to emerging adulthood. As expected, early users were at relatively high risk for poor outcomes at age 23 compared to consistent low-level users and abstainers, even if they reduced their use during adolescence. However, youths who were not early users, but steadily increased their use over time, also tended to be at relatively high risk. Results suggest that multiple prevention approaches might be needed to successfully reach at-risk youths.