Frequent solitary drinking mediates the associations between negative affect and harmful drinking in emerging adults

Introduction: Depression and anxiety are highly comorbid conditions that are associated with harmful drinking. Social learning theory proposes that depressed or anxious individuals learn that drinking can reduce negative affect, which makes them susceptible to harmful drinking. Consistent with theory, evidence suggests that negative affect increases risk for harmful drinking. But, less is known about mediators of negative affect-pathways to harmful drinking. Research has demonstrated that solitary drinking is an underlying mechanism of harmful drinking among emerging adults with high levels of negative affect. However, much of this work is cross-sectional. We conducted a longitudinal study to examine solitary drinking as a key explanatory variable in the negative-affect pathway to harmful drinking. Methods: Emerging adults (N = 308) completed online self-reports of depression and anxiety at Time 1 (the beginning of their first semester in university), and drinking context and harmful drinking at Time 2 (the end of their first semester of university). Results: Structural equation modeling supported indirect effects from negative affect to harmful drinking via solitary drinking. Specifically, emerging adults with high levels of negative affect at the beginning of their first semester engaged in frequent solitary drinking over the rest of the semester, and subsequently experienced increased harmful drinking (controlling for Time 1 solitary/social drinking and harmful use). Social drinking was not a mediator of this effect. Conclusions: The findings reveal that solitary drinking uniquely mediated the relation between negative affect and harmful drinking. Reducing solitary drinking might mitigate negative affect-related risk for harmful drinking in emerging adults.