Alcohol consumption and major depression: findings from a follow-up study.

OBJECTIVE To investigate whether alcohol consumption predicts major depressive disorder episodes (MDEs) in the general population. METHOD The respondents without depression (n = 12,290) in the longitudinal cohort of the Canadian National Population Health Survey (NPHS) were classified into cohorts based on any drinking, frequency of drinking, maximum number of drinks on a maximal drinking occasion, and average daily alcohol consumption, based on data collected in the 1994-1995 survey. Major depression frequency 2 years later, in 1996-1997, was evaluated and compared across drinking categories. RESULTS The respondents who reported any drinking, drinking daily, having more than 5 drinks on a maximal drinking occasion, and having more than 1 drink daily on average, did not have an elevated risk of major depression. A trend in the data suggested that women who reported having more than 5 drinks on a maximal drinking occasion might be at a higher risk of major depression. No evidence of confounding or effect modification by demographic, psychological, and clinical variables was found. CONCLUSION In a general population sample, alcohol consumption levels were not associated with major depression. Having more than 5 drinks on a maximal drinking occasion, however, may be associated with an increased risk of major depression among women. Extreme patterns of alcohol consumption, which tend to characterize clinical samples, are associated with depression. These patterns of drinking, however, are relatively uncommon in the general population, and the current analysis may have lacked power to detect these associations.