Investigating the association between moderate drinking and mental health

In an attempt to relate "moderate drinking" to "mental health," inadequacies of definition for both terms become apparent. Moderate drinking can be variously defined by a certain number of drinks to "nonintoxicating" to "noninjurious" to "optimal," whereas mental health definitions range from "the absence of psychopathology" to "positive psychology" to "subjective well-being." Nevertheless, we evaluated the relation by conducting an electronic search of the literature from 1980 onwards using the terms "moderate drinking," "moderate alcohol consumption," "mental health," and "quality of life." Most studies report a "J-shaped curve," with positive self-reports of subjective mental health associated with moderate drinking but not with heavier drinking. The relevance of expectancies has been unevenly acknowledged, and studies on the cultural differences among expectancies are largely lacking. The potential role of moderate drinking in stress reduction and studies of social integration have yielded inconsistent results as previous levels of drinking, age, social isolation, and other factors have often not been adequately controlled. Future anthropological, epidemiological, and pharmacological interactions preferably must be studied through a prospective design and with better definitions of moderate drinking and mental health.