Behavioral approach system moderates the prospective association between the behavioral inhibition system and alcohol outcomes in college students.

OBJECTIVE: Reinforcement sensitivity theory (RST) is a useful framework for understanding alcohol use, including problematic drinking among college students. Although the link between the behavioral approach system (BAS) and drinking is well established, the role of the behavioral inhibition system (BIS) is less well studied, and findings have been mixed. Consistent with RST, the relationship between BIS and problematic drinking may be moderated by BAS, but tests of the BIS × BAS interaction have been scarce. We hypothesized that high BIS would be a risk factor for subsequent problematic drinking in combination with an elevated BAS, whereas BIS would protect against subsequent problematic drinking in the context of low levels of BAS.
METHOD: College student drinkers (N = 638; 66% women) at two universities completed online measures of BIS, BAS, alcohol use, and alcohol problems at matriculation (Time 1 [T1]) and again 1 year later (Time 2 [T2]).
RESULTS: Regression analyses of alcohol use and problems were performed with BIS, BAS, and the BIS × BAS interaction as predictors. The interaction was not statistically significant in cross-sectional models (T1 alcohol outcomes), but it was a significant prospective predictor of T2 alcohol use (marginal) and T2 alcohol problems. Simple slopes analyses revealed that BIS was a positive predictor of T2 alcohol use and problems at high but not low levels of BAS, albeit this effect was less reliable for use.
CONCLUSIONS: Our findings enhance interpretation of RST, demonstrating a complex link between BIS and problematic drinking risk, one that is moderated by BAS. The prospective nature of these associations suggests that, together, BIS and BAS may promote increases in problematic drinking over time, highlighting the need for targeted interventions during the first year of college.