Brief Motivational Interventions Are Associated with Reductions in Alcohol-Induced Blackouts Among Heavy Drinking College Students.

Abstract

Alcohol-induced blackouts, a form of anterograde amnesia that restricts the encoding of short-term memories into long-term ones, are among the most severe alcohol-related consequences. College students are at high risk of experiencing alcohol-induced blackouts, and there is a need to determine whether alcohol interventions can effectively reduce blackouts in this population. The current study uses data from 3 randomized clinical trials to examine the effect of various intervention approaches on alcohol-induced blackouts. Four interventions were compared over 3 studies: (i) a computerized feedback intervention (electronic Check-Up To Go [e-Chug]; Study 1); (ii) a single-session brief motivational intervention (BMI; Study 1); (iii) a BMI plus behavioral economic session focused on increasing substance-free activities (BMI+Substance-Free Activity Session [SFAS]; Studies 2 and 3); and (iv) a BMI plus supplemental Relaxation Training session (BMI+Relaxation Training; Studies 2 and 3). Studies 1 and 3 also included an assessment-only control condition. For each study, participants reported whether they had experienced an alcohol-induced blackout at each time point; binary logistic regressions examined differential likelihood of experiencing an alcohol-induced blackout over time. Neither the single-session BMI nor e-Chug reduced alcohol-induced blackouts over assessment only; however, participants in the BMI+SFAS or BMI+Relaxation Training condition were significantly less likely to experience an alcohol-induced blackout compared to assessment only at 1-month (Wald=4.77, odds ratio [OR]=0.53, p=0.03) and 6-month follow-ups (Wald=5.72, OR=0.52, p=0.02). Study 2 also revealed a larger effect for the BMI+SFAS over the BMI+Relaxation Training condition at 6months (Wald=4.11 OR=0.22, p=0.043), although this was not replicated in Study 3. The effects for the 2-session BMIs lasted 6months, at which point maturation effects diminished differences between assessment-only and intervention conditions. Two sessions of BMI are a substantial enough dose to result in reductions in alcohol-induced blackouts among college student heavy drinkers.