Accelerated alcohol use across adolescence predicts early adult symptoms of alcohol use disorder via reward-related neural function.

BACKGROUND: Alcohol use is commonly initiated during adolescence, with earlier onset known to increase the risk for alcohol use disorder (AUD). Altered function in neural reward circuitry is thought to increase the risk for AUD. To test the hypothesis that adolescent alcohol misuse primes the brain for alcohol-related psychopathology in early adulthood, we examined whether adolescent alcohol consumption rates predicted reward responsivity in the ventral striatum (VS), and in turn, AUD symptoms in adulthood.
METHODS: A total of 139 low income, racially diverse urban males reported on their alcohol use at ages 11, 12, 15, and 17; completed self-reports of personality, psychiatric interviews, and a functional magnetic resonance imaging (fMRI) scan at age 20; and completed a psychiatric interview at age 22. We measured adolescent alcohol use trajectories using latent growth curve modeling and measured neural responses to monetary reward using a VS region of interest. We tested indirect effects of adolescent alcohol use on AUD symptoms at age 22 via VS reward-related reactivity at age 20.
RESULTS: Greater acceleration in adolescent alcohol use predicted increased VS response during reward anticipation at age 20. VS reactivity to reward anticipation at age 20 predicted AUD symptoms at age 22, over and above concurrent symptoms. Accelerated adolescent alcohol use predicted AUD symptoms in early adulthood via greater VS reactivity to reward anticipation.
CONCLUSIONS: Prospective findings support a pathway through which adolescent alcohol use increases the risk for AUD in early adulthood by impacting reward-related neural functioning. These results highlight increased VS reward-related reactivity as a biomarker for AUD vulnerability.