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.