Patterns of association between alcohol consumption and internalizing and externalizing problems in young adults

Objective: This study examined levels of internalizing and externalizing problems over the full spectrum of alcohol consumption in young adults and identified whether social factors account for the associations of alcohol consumption with internalizing and externalizing problems. Method: This study was a cross-sectional random sample study among 2,258 young adult men and women from the general population of southwest Netherlands. Five groups were distinguished: (1) nondrinkers; (2) occasional drinkers (monthly or less); and regular drinkers (two or more times monthly) who were further classified into (3) low-level drinkers (one to two drinks per occasion), (4) higher-level drinkers (three to four drinks per occasion), or (5) excessive drinkers (five or more drinks per occasion). Internalizing problems and externalizing problems, social support, and negative social exchange were measured with standardized questionnaires. Results: U-shaped associations were found between alcohol consumption and various internalizing problems. Low social support accounted for higher rates of internalizing problems in nondrinkers and negative social exchange accounted for higher rates of internalizing problems in excessive drinkers. Also, excessive drinking was associated with various externalizing problems. A J-shaped association was found between alcohol consumption and aggressive behavior, with higher rates for occasional and excessive drinkers compared with low-level drinkers. Negative social exchange partly accounted for associations between alcohol consumption and externalizing problems. Conclusions: Nondrinkers and excessive drinkers differ from low-level drinkers in risk factors for poor mental health, and these factors may contribute to their elevated rates of mental health problems. Interventions that address the experience of negative social exchange may produce both mental health benefits and a reduction of excessive drinking