Abstract
BACKGROUND: The purpose of this study was to evaluate intraindividual variation in "maturing out" of alcohol use by using latent class growth trajectories of alcohol use from adolescence (age 17 years) through young adulthood (age 33 years). We also modeled trajectory group differences with regard to concurrent, age-relevant domains of substance use, health (e.g., physical health rating, sleep problems), interpersonal functioning (e.g., conflict with partner), and occupational functioning (e.g., intrinsic motivation). METHODS: Growth mixture modeling was used with a sample of 1,004 adolescents/young adults, and 3 trajectory groups were identified as follows: (i) a Normative Use group (n = 646) with low alcohol use remaining stable from adolescence to young adulthood; (ii) a Moderate Increase group (n = 300) with moderate alcohol use increasing slowly from adolescence to emergent adulthood (age 23 years) and then decreasing slightly from emergent adulthood to young adulthood (age 33 years); and (iii) a High Increase group (n = 58) with a high, increasing pattern of alcohol use from adolescence to emergent adulthood and then a small decrease in use from emergent adulthood to young adulthood. RESULTS: At age 33 years, trajectory groups differed, with High and Moderate Increase groups differing significantly from the Normative Use group in current alcohol and other substance use and other risk factors (e.g., friends' alcohol use). Furthermore, the High and Moderate Increase groups differed from the Normative Use group on indicators of health (poorer sleep and more sleep problems), social functioning (higher partner and work-family conflict), and occupational functioning (lower intrinsic work motivation). CONCLUSIONS: These findings suggest that trajectory group membership in alcohol use from adolescence to young adulthood is associated with the domains of substance use, health, and social and occupational functioning. Furthermore, the findings suggest that maturing out applies primarily to a subset of those individuals at moderate to higher levels of alcohol use.