Associations among alcohol sensitivity, acquired tolerance, and drinking outcomes in late adolescence.

Alcohol tolerance is a core diagnostic feature of alcohol use disorder, yet little research has investigated its role in risky drinking during late adolescence. Low sensitivity to alcohol sedation is also linked to alcohol use disorder risk, but few studies have examined how acquired tolerance and alcohol sensitivity concurrently relate to heavy drinking. This study examined the concurrent and prospective associations of acquired tolerance and alcohol sensitivity with heavy drinking among late adolescent heavy drinkers (N = 308, ages 18-21, 52.6% female). At baseline, participants completed self-report measures of acquired tolerance, early and current alcohol sensitivity, and alcohol-consumption outcomes. Analyses tested for differences in alcohol tolerance and sensitivity by family history (FH) of alcohol use disorder and path analyses examined associations and indirect effects from a positive FH and age at first/regular drinking to alcohol sensitivity, acquired tolerance, and heavy drinking. Positive FH and early regular drinking were associated with greater acquired tolerance, lower sensitivity to alcohol sedation, and greater heavy drinking. In supplemental prospective analyses involving a subset of partcipants who completed a 1-year follow-up, acquired tolerance predicted 1-year follow-up heavy drinking, whereas alcohol sensitivity did not. Concurrent indirect effects from positive FH and early regular drinking to heavy drinking episodes, through acquired tolerance and low sedation sensitivity, were found; however, prospective indirect effects were only found through acquired tolerance. Findings suggest that acquired tolerance may represent a key mechanism linking a positive FH and early regular drinking to heavy drinking in late adolescence. (PsycInfo Database Record (c) 2026 APA, all rights reserved).