* New findings indicate that depression is primarily related to binge drinking.
* The relationship between major clinical depression and alcohol consumption appears to be stronger for women than it is for men.
* However, men and women do not differ in the relationship between alcohol use and depression when depression is measured as recent feelings of depression or unhappiness.
Although previous research has shown that alcohol consumption and depression are often related, the findings have not been consistent. A new study has found that how researchers measure both alcohol consumption and depression, as well as examination by gender, are key issues when interpreting findings on the relationship between alcohol and depression.
Results are published in the January issue of Alcoholism: Clinical & Experimental Research.
"Not all studies have found a significant relationship between drinking and depression," said Kathryn Graham, senior scientist at the Centre for Addiction and Mental Health, "and some have found a relationship for one gender but not the other. In our study, we included two quite different types of measures of depression. We also used four clearly different types of alcohol consumption measures that examined both drinking pattern as well as overall consumption." Graham is the corresponding author for the study.
"This is an important study of a large national sample of Canadian women and men," added Sharon C. Wilsnack, Chester Fritz Distinguished Professor at the University of North Dakota School of Medicine & Health Sciences. "It looks at associations between depression and alcohol use separately for women and for men. It is clear from the study's results that it is a mistake to analyze relationships between depression and alcohol consumption without specifying which manifestations of depression are linked to which drinking patterns. And even when multiple measures are used, the connections are more evident among women than among men."
Researchers conducted a general population telephone survey of 6,009 males and 8,054 females aged 18 to 76 years. The study included four types of alcohol measures given for both the past year and the week prior to the survey: frequency of drinking, usual and maximum quantity per occasion, overall volume, and heavy episodic drinking; and two types of depression measures: meeting criteria for a clinical diagnosis of major depression, and recent depressed feelings.
Results indicate that measurement and gender are key issues in interpreting findings on the relationship between alcohol and depression. Specifically, depression is primarily related to drinking larger quantities per occasion, is unrelated to drinking frequency, and these effect are stronger for women than for men.
"Depression is most strongly related to a pattern of binge drinking," said Graham. "A pattern of frequent but low quantity drinking is not associated with depression. In fact, those who usually drink less than two drinks per occasion and never drink as much as five drinks are less depressed - for both measures of depression - than former drinkers. This relationship with drinking pattern is greater for women than for men."
Second, the overall relationship between depression and alcohol consumption is stronger for women than for men, but only when depression is measured as meeting a clinical diagnosis of major depression. Conversely, there is no gender difference when depression is measured as recent depressed feelings, which is commonly done in research on this topic.
"This pattern of associations is more consistent with women using alcohol to counteract depression - by high-quantity drinking and intoxication - than with chronic alcohol consumption tending to make women depressed," said Wilsnack. "However, a vicious circle could possibly begin with drinking in response to depression. This study underscores the important fact that women and men differ in significant ways - both biologically and socially - that may impact how they drink, and the predictors and consequences of their drinking behavior."
"These findings provide critical clarification of the relationship between alcohol consumption and depression that will be essential for future research intended on identifying causal directions and mechanisms," said Graham. "For example, in the past longitudinal research has been conducted attempting to disentangle the alcohol-depression relationship in order to identify whether alcohol consumption leads to depression, depression leads to alcohol consumption, or some third factor associated with both alcohol consumption and depression accounts for the relationship. No clear pattern has emerged from these studies. Systematic consideration of the types of measures for alcohol consumption and depression and gender may lead to clearer, more consistent findings."
Wilsnack added that future research might also attempt to specify how the social context of drinking may affect the links between depression and drinking. For example, she said, "the association of clinical depression with episodes of heavy drinking may be stronger for women who have heavy-drinking partners and/or who have more social opportunities to drink."
The bottom line, said Wilsnack, is that "clinical depression may encourage some women to drink large amounts of alcohol in hopes of numbing depressed feelings, with risks of alcohol abuse and dependence. Therefore, clinicians treating women for depression really need to be concerned about women's use of alcohol, because of the risks that women may try to medicate their moods with alcohol."
Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, "Does the Association Between Alcohol Consumption and Depression Depend on How They Are Measured?," were: Agnes Massak of the Department of Psychology at the University of Western Ontario; Andrée Demers of the Groupe de recherche sur les aspects sociaux de la santé et de la prévention; and Jügen Rehm of the Public Health and Regulatory Policies Centre for Addiction and Mental Health. The study was funded by the Canadian Institutes of Health Research.
Kathryn Graham, Ph.D.
Centre for Addiction and Mental Health
Sharon C. Wilsnack, Ph.D.
University of North Dakota School of Medicine & Health Sciences
Alcoholism: Clinical & Experimental Research