Although previous research has documented an association between alcohol use, its consequences, and depression, ascertaining the causality of this relationship has been difficult. A new study attempted to clarify this association among female college students using a prospective longitudinal design. Participants (N = 483) were female undergraduates aged 18 to 25 years at one U.S. college who did not have histories of depression or other mood disorders. Two analytic samples were used: (1) combined drinkers and non-drinkers (n = 396) and (2) past-year drinkers (n = 274). The former sample was used to examine the effect of alcohol consumption on the onset of depression, while the latter was used to examine the effect of drinking consequences on the onset of depression. Participants in both samples completed a baseline survey during their first month on campus, followed by 12 monthly follow-up surveys. Survey measures included time to onset of depression (as measured by the Patient Health Questionnaire-9 [PHQ-9]), average drinks per week in the past month, frequency of heavy episodic (‘binge’) drinking, sociodemographic characteristics, social connectedness, perceived academic challenge in college, relationship with one’s roommate, previous sexual victimization, and past-month marijuana use. At each time point, participants also indicated the number of alcohol-related consequences they had experienced in the past month using a list of 12 potential consequences (e.g., feeling hungover, missing class) compiled by the authors. Chi-square tests and t-tests were used to compare sociodemographic characteristics of participants who developed depression; Kaplan-Meier method and log-rank tests were used to assess whether time to onset of depression varied by the primary exposures measured at baseline. The authors also employed multivariable Cox proportional hazards regressions with time-varying covariates to assess the relationship between drinks consumed per week and depression in the full sample and the relationship between alcohol consequences and depression onset among drinkers. Results indicated 80% of the full sample and 90% of drinkers reported engaging in heavy episodic drinking at least once during follow-up. Among drinkers, the mean number of monthly consequences reported ranged from 1.52 (Standard deviation [SD] = 0.13) to 2.10 (SD = 0.15). Twenty-three percent (n = 93) of the full sample experienced depression onset during the study, compared to 19% (n = 23) of drinkers. Depression onset was unrelated to alcohol consumption at baseline (p = 0.48). Alcohol consequences were prospectively associated with depression onset among drinkers (Adjusted hazard ratio [AHR]: 1.19; 95% confidence interval [CI]: 1.05-1.34).

Take away: Among this sample of female undergraduates, 23% developed depression during their first year of college. Alcohol consumption at baseline was not significantly associated with depression onset, but alcohol-related consequences predicted depression onset among participants who drank at baseline.

Rosenthal, S.R., Clark, M.A., Marshall, B.D.L., Buka, S.L., Carey, K.B., Shepardson, R.L. & Carey, M.P. (2018). Alcohol consequences, not quantity, predict major depression onset among first-year female college students. Addictive Behaviors [published online ahead of print May 25, 2018] doi: 10.1016/j.addbeh.2018.05.021