Low-to-Moderate Alcohol Intake Associated with Lower Risk of Incidental Depressive Symptoms: A Pooled Analysis of Three Intercontinental Cohort Studies.

BACKGROUND

The existing findings of the longitudinal impact of low-to-moderate drinking on symptomatic depression were controversial, as results ranged from finding no association to finding both a protective and adverse association.

METHODS

The present study examined the association between low-to-moderate alcohol consumption and incident depressive symptoms by pooled analysis of three European, American and Chinese representative samples of middle-aged and older adults.

RESULTS

A total of 29,506 participants (55.5% female) were included. During 278,782 person-years of follow-up, we found that subjects with low-to-moderate drinking had a significantly lower incidence of depressive symptoms compared to never-drinking subjects, with pooled hazard ratios of 0.87 (95% confidence interval [CI]: 0.79-0.96) for men and 0.87 (95% CI: 0.80-0.95) for women, whereas heavy drinkers failed to show significantly higher risk of depressive symptoms. Furthermore, a J-shaped relation between alcohol consumption and incident depressive symptoms was identified in Chinese men, US men, and UK men and women.

LIMITATIONS

The classification of depressive symptoms based on the Center for Epidemiologic Studies Depression Scale may not be completely comparable to diagnosis from a clinical setting.

CONCLUSIONS

Low-to-moderate alcohol consumption was significantly associated with a lower risk of depressive symptoms on a long-term basis compared to never drinking. Our results support the threshold of moderate drinking in current US guidelines. However, caution should be exercised in engaging in guideline-concordant drinking habits, for even moderate drinkers are at risk of developing heavy drinking habits and experiencing future alcohol-related problems.