Alcohol consumption predicts incidence of depressive episodes across 10 years among older adults in 19 countries.

Alcohol consumption is increasing in many countries, and excessive alcohol consumption is particularly increasing among older adults. Excessive alcohol consumption causes morbidity and mortality, especially among older adults, including an increased risk of depressive episodes. We review the mechanisms through which alcohol consumption may affect depression, and argue that the effects of alcohol consumption on depressive episodes among older adults are understudied. We harmonized data among older adults (≥50 years) on alcohol consumption, depressive episodes, and an array of risk factors across 10 years and 19 countries (N=57,276). Alcohol consumption was categorized as current or long-term abstainer, occasional, moderate and heavy drinking at an average of 2.3 follow-up time points. Depressive episodes were measured through the CES-D or EURO-D. Multi-level Cox proportional frailty models in which the random effect has a multiplicative relationship to hazard were estimated with controls for co-occurring medical conditions, health behaviors, and demographics. Long-term alcohol abstainers had a higher hazard of depressive episodes (HR=1.14, 95% C.I. 1.08-1.21), as did those reporting occasional (HR=1.16, 95% C.I. 1.10-1.21) and heavy drinking (HR=1.22, 95% C.I. 1.13-1.30), compared with moderate drinking. Hazard ratios were attenuated in frailty models; heavy drinking, however, remained robustly associated in a random-effects model with a frailty component (HR=1.16, 95% C.I. 1.11-1.21). Interactions were observed by gender and smoking status: long-term abstainers, women's, and smokers' (HR for interaction, 1.04, 95% C.I. 1.00-1.07) hazards of depressive episodes increased more than what would be expected based on their multiplicative effects, when compared to moderate drinking, non-smoking men. Excessive alcohol consumption among older adults is a concern not only for physical, but also for mental health. Physician efforts to screen older adults for excessive alcohol use is critical for mental health to remain strong in aging populations.