Alcohol-Induced Blackouts and Subsequent Drinking Trajectories: Evidence From Three Longitudinal Samples

Alcohol-induced blackouts are widely recognized as markers of acute intoxication and elevated risk for alcohol-related harm. Blackout experiences may also represent psychologically salient events capable of influencing subsequent drinking behavior. The present study examined whether recent blackout predicts changes in alcohol use, alcohol-related consequences, and blackouts over time.

Data were drawn from three independent longitudinal samples of college student drinkers (Ns = 568, 484, and 200). Generalized linear mixed models with negative binomial distributions were used to evaluate whether baseline blackout status predicted follow-up drinks per week, alcohol-related consequences, and subsequent blackouts over 12 months of follow-up, controlling for baseline drinking and consequences, age, sex, intervention condition, and time.

Across samples, baseline blackout was not associated with increases in subsequent alcohol use. In one sample, blackout predicted lower follow-up drinking, and in two of three samples, blackout predicted significantly lower rates of alcohol-related consequences over time (i.e., a 21%-40% reduction in consequences among those who experienced a blackout across follow-ups). Conversely, baseline blackout was associated with increased odds of subsequent blackout across all samples. These associations were found after adjusting for baseline alcohol-related consequences and concurrent drinking.

Blackouts may function not only as a marker of high-risk drinking but also as a potential turning point associated with reductions in alcohol-related harm. At the same time, effects were not uniform across samples. Results underscore the importance of assessing blackout in research and clinical settings, and they highlight its potential dual role as both a risk indicator and a catalyst for behavioral change.