Solitary drinking as a day-level risk factor for unique negative consequences among college students

Solitary drinking represents a high-risk pattern of drinking across individuals but when examined within individuals, solitary moments are associated with less risk. One possibility is that solitary drinking confers risk for specific negative consequences at the day level, but aggregate measures of negative consequences mask such relations. Thus, this study examined the extent to which solitary drinking increased the likelihood of reporting specific negative consequences, controlling for drinking quantity.

College students (N = 1043; 51.8% female) completed a 30-day Timeline Followback Interview in which they reported day-level drinking context, drinking quantity, and negative consequences. A total of 7340 drinking days were reported. Two-level multilevel probit regressions with Bayesian estimation tested whether drinking context (i.e., solitary vs. social) was associated with an increased likelihood of experiencing each of eight unique negative consequences (i.e., social/interpersonal, risky behavior, blackouts, occupational, impaired control, physical dependence, self-care, and self-perception), controlling for drinking quantity.

When controlling for drinking quantity, solitary (vs. social) drinking days were associated with a higher likelihood of occupational consequences [β = 0.05, 95% BCI = (0.01, 0.08)] and diminished self-perception [β = 0.06, 95% BCI = (0.03, 0.10)]. Solitary drinking days were also associated with a lower likelihood of interpersonal consequences (β = -0.06, 95% BCI = [-0.11, -0.03]) and blackout drinking (β = -0.06, 95% BCI = [-0.09, -0.03]). Person-level results suggest that those who more often drink alone experience greater blackout drinking, impaired control, dependence, occupational consequences, and diminished self-perception (all p's < 0.001). When consequences were summed, solitary drinking days (vs. social) were associated with fewer negative consequences (β = -0.023, 95% BCI = [-0.049, -0.005]), whereas at the person level, those who more frequently drink alone experienced more negative consequences (β = 0.10, 95% BCI = [0.04, 0.17]).

Results suggest that social and solitary drinking contexts confer risk for specific consequences and that risk for consequences differs if consequences are aggregated. Findings may inform future interventions by emphasizing certain protective behavioral strategies in specific drinking contexts to reduce the likelihood of negative outcomes.