Does moderate drinking help in depression?

The beneficial effect of moderate alcohol consumption in preventing depression appears causal, suggest the results of a recent study.

A group of researchers performed a secondary analysis of the National Longitudinal Survey of Youth 1979 cohort and employed a marginal structural model (MSM) approach to compare the effects of consistent abstinence and occasional, moderate, and above-guideline alcohol consumption throughout early to middle adulthood on depression at age 50 years.

The year 1994, when participants were 29‒37 years of age, was set as the baseline. The MSM involved measurements of alcohol intake in 1994, 2002, and 2006; baseline and time-varying covariates; and repeated measurements with the Center for Epidemiologic Studies Depression Scale‒Short Form (CES-D-SF).

Overall, 5,667 participants met the eligibility criteria and had valid data at baseline. Of these, 3,593 provided valid outcome data. The authors then used relevant information to predict CED-D-SD means and rates of probable depression for hypothetical trajectories of consistent alcohol intake.

A J-curve association was observed, with both consistent occasional and consistent moderate alcohol consumption correlating with lower CES-D-SF scores and rates of probable depression at age 50 years relative to consistent abstainers (CES-D-SF scores: b, −0.84, 95 percent confidence interval [CI], −1.47 to −0.11; probable depression: odds ratio [OR], 0.58, 95 percent CI, 0.36‒0.88 for consistent occasional drinkers vs abstainers; CES-D-SF scores: b, −1.08, 95 percent CI, −1.88 to −0.20; probable depression: OR, 0.59, 95 percent CI, 0.26‒1.13 for consistent moderate drinkers vs consistent abstainers).

On the other hand, consistent above-guideline drinkers tended to have a slightly higher risk than consistent abstainers, but the association did not reach significance. Sex-stratified analyses revealed similar results for males and females.

“This study contributes preliminary evidence that associations between moderate alcohol consumption and reduced risk for depression may reflect genuine causal effects,” the researchers said. “Further research using diverse methodologies that promote causal inference is required.”