Men and women at risk for alcohol dependence are more likely to choose a mate who also is at risk, say investigators at Washington University School of Medicine in St. Louis. That doesn't necessarily mean, however, that both spouses will end up as problem drinkers.

Alcoholism is more common among partners of alcoholics than among partners of non-alcoholics, but it isn't as common as it might be. The researchers found that in some cases, one spouse's excesses with alcohol actually could help protect the other from alcohol dependence.

A team of researchers from Washington University and from the Queensland Institute of Medical Research in Brisbane, Australia, studied 5,974 twins born between 1902 and 1964 who were part of the Australian Twin Register. They also spoke with 3,814 of those twins' spouses for the study, published in the May issue of the journal Alcoholism: Clinical & Experimental Research.

"As they say, 'like marries like,'" says first author Julia D. Grant, Ph.D., research assistant professor of psychiatry at Washington University. "Spouse selection is not a random process, and we call this non-random mating. People tend to choose mates who are similar to them, not only from the same neighborhood or socio-economic background but also alike in personality and other behaviors. We found that people at risk for alcohol dependence tend to marry others who are at risk."

Alcohol dependence is influenced by both genetic and environmental factors. Genetic influences explain about half of the variance in a person's total risk for alcohol dependence. The other half of an individual's risk for alcohol dependence comes from environmental factors such things as employment, interests, friends and family.

"There's lots of room for different factors to influence the behavior of two people who are married," Grant says. "One spouse could work at a place where the co-workers go out for a drink after work. Or one spouse c
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Contact: Jim Dryden
jdryden@wustl.edu
314-286-0110
Washington University School of Medicine
2-May-2007