FRIDAY, Nov. 29, 2013 (HealthDay News) -- Heavy drinking by one partner in a marriage increases the risk of divorce, but that's not the case if both spouses are heavy drinkers, a new study finds.
Researchers followed nearly 650 couples for the first nine years of their marriage and found that the divorce rate was nearly 50 percent for couples where only one partner drank heavily. Heavy drinking was defined as having six or more drinks at one time or drinking to intoxication.
The divorce rate for couples where neither were heavy drinkers and for couples where both were heavy drinkers was 30 percent, according to the study, published in the December issue of Psychology of Addictive Behaviors.
"Our results indicate that it is the difference between the couple's drinking habits, rather than the drinking itself, that leads to marital dissatisfaction, separation and divorce," lead author Kenneth Leonard, director of the University at Buffalo Research Institute on Addictions, said in a university news release.
"This research provides solid evidence to bolster the commonplace notion that heavy drinking by one partner can lead to divorce. Although some people might think that's a likely outcome, there was surprisingly little data to back up that claim until now," he added.
The researchers were surprised that the divorce rate for two heavy drinkers was no higher than for two nondrinkers.
"Heavy drinking spouses may be more tolerant of negative experiences related to alcohol due to their own drinking habits," Leonard said.
But this does not mean that heavy drinking by both partners does not damage other areas of family life. "While two heavy drinkers may not divorce, they may create a particularly bad climate for their children," he noted.
Leonard concluded: "Ultimately, we hope our findings will be helpful to marriage therapists and mental health practitioners who can explore whether a difference in drinking habits is causing conflicts between couples seeking help."
The U.S. National Institute on Alcohol Abuse and Alcoholism outlines the health effects of alcohol.
SOURCE: University at Buffalo, news release, Nov. 26, 2013