REVIEW PAPER

Alcohol Consumption and Major Depression: Findings From a Follow-Up Study
JianLi Wang, PhD1, Scott B Patten MD, FRCPC, PhD2

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.

(Can J Psychiatry 2001;46:632–638)

Key Words: alcohol consumption, major depression

Cross-sectional studies using community samples have provided evidence that heavy alcohol use is associated with an elevated risk of depressive symptoms (1,2) and major depression (3–5). It remains unclear whether alcohol consumption is a causal factor for major depression. Relevant information has significant public health and clinical implications in terms of formulating prevention strategies and managing depressive disorders. Yet, few prospective studies using community-based samples have evaluated the relation between alcohol consumption and depression.

The existing follow-up studies that use community samples failed to find an association between alcohol consumption and depressive symptoms (6,7). Moscato and others followed 1358 household subjects from 1986 to 1993 (6). They examined whether the initial alcohol problems predict depressive symptoms. The subjects were considered to have alcohol problems if they met DSM-III criteria for alcohol abuse or dependence in the previous year or reported having 5 drinks or more daily, at least 1 to 2 times weekly in the previous year. Depressive symptoms were evaluated using the Center for Epidemiological Studies–Depression Scale (CES-D). Alcohol problems were not found to predict depressive symptoms.

Manuscript received April 2000, revised, and accepted June 2001.
1Post-Doctoral Fellow, Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia.
2Associate Professor, Departments of Community Health Sciences and Psychiatry, Faculty of Medicine, University of Calgary, Calgary, Alberta.
Address for correspondence: Dr J Wang, Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, 5849 University Ave, Halifax, NS.B3H 4H7.
e-mail:Jwang@tupdean2.med.dal.ca


In another study, Lipton classified subjects into groups of abstainers, light drinkers, light-moderate drinkers, moderate drinkers, and heavy drinkers (7). One year later, the subjects were evaluated using the CES-D, and it was found that the mean CES-D scores did not differ significantly between light or no drinking and heavy drinking groups. Similarly, a recent metaanalysis study (8) failed to find evidence that initial alcohol consumption levels per occasion predicted later depressive symptoms (ranged from 2 to 10 years).

As noted above, most existing studies have measured depressive symptoms rather than depressive disorders. Depressive symptoms do not necessarily indicate clinically significant depressive disorders, such as major depression. Schuckit and others conducted a 12-month follow-up study to measure the incidence of major depression by DSM-III-R criteria among 239 alcoholic men in an inpatient setting (9). In their study, they failed to find a significant difference between the incidence of major depression during heavy drinking and the incidence of major depression independent of heavy drinking. Similarly, Hodgins and others found no evidence that heavy drinking could reliably predict later occurrence of major depression, using a clinical sample (10). Data from clinical populations, however, may not apply in the general population and may not be a suitable basis for forming public health policy.

The Canadian National Population Health Survey (NPHS) provides a unique opportunity to examine the relation between alcohol consumption and major depression in a prospective perspective.

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