Predictors and Outcomes of Variability in Subjective Alcohol Intoxication Among College Students: An Event-Level Analysis Across 4 Years

Background: Individual differences in subjective alcohol intoxication, as measured by laboratory-based alcohol challenge, have been identified as a phenotypic risk factor for alcohol use disorders. Further, recent evidence indicates that subjective alcohol response is also associated with event-level physiological consequences among college students, including blackouts and hangovers. Methods: The current investigation tested predictors of and outcomes associated with subjective intoxication in the natural drinking environment. In a preliminary laboratory alcohol-challenge study (n = 53), we developed a brief measure of subjective alcohol intoxication for use in event-level research. Participating students in the principal study (n = 1,867; 63% women; 54% Caucasian) completed 30 days of Web-based self-monitoring in each of the 4 college years. Results: In the principal study, generalized estimating equation analyses revealed that both lighter drinking and a family history of alcohol problems predicted greater subjective intoxication after accounting for estimated blood alcohol concentration (eBAC). Moreover, greater subjective intoxication during a given drinking episode was associated with negative alcohol-related consequences, illicit drug use, and unsafe sex, and at higher eBACs, was associated with aggression, sex, and property crime. Students who on average experienced greater subjective intoxication were also more likely to experience negative consequences and engage in illicit drug use, sex, unsafe sex, and aggression. Conclusions: These findings suggest that both within-person variability and between-person individual differences in subjective intoxication may be risk factors for adverse drinking outcomes at the event level. Intervention efforts aimed at reducing problems associated with collegiate drinking may benefit from consideration both of who experiences greater subjective intoxication and of the situations in which they are more likely to do so.