Internalizing and externalizing subtypes of alcohol misuse and their relation to drinking motives

Background: Several typologies have proposed two etiological pathways involved in the development of alcohol misuse which are associated with the internalizing and externalizing domains of psychopathology, respectively. This study's aim was to investigate this typology in a young adult sample, and test whether drinking motives, specifically drinking for negative or positive reinforcement, may provide a plausible mechanism characterizing these pathways. Method: Mixture modeling was conducted on a set of internalizing (anxiety, depression, neuroticism), externalizing (antisocial behavior, conscientiousness, sensation seeking, drug use), and alcohol misuse items (binge drinking, alcohol use disorder symptoms [AUDsx]) measured by self-report in a sample of 9,807 college students. Linear regression and chi-square tests were used to determine how latent class membership was associated with drinking motives, demographics, and personality characteristics. Results: The model identified 3 latent classes: a Low Risk class (70%), an Internalizing class (19%) with elevated levels of internalizing traits/symptoms and AUDsx, and an Externalizing class (10%) with elevated levels of externalizing traits/symptoms and both binge drinking and AUDsx. All drinking motives were substantially elevated in the Internalizing and Externalizing (vs Low Risk) classes (p < 3.0E-10), while positive reinforcement motives were specifically elevated in the Externalizing (vs Internalizing) class (p < 2.0E-55). Personality comparisons further emphasized the relevance of class distinctions. Conclusions: These findings provide additional support for both a specific internalizing and a broadband externalizing association with subtypes of alcohol misuse. Drinking motives may be useful intermediate indicators of these different risk processes.