Women have as strong an inherited susceptibility to alcoholism as men, a new report shows.
In recent years, several studies have shown that in men genetics accounts for 50 to 60 percent of the factors that determine a person's vulnerability to a severe drinking problem. The new study, published today in the Journal of the American Medical Association, shows that the same magnitude holds for women, said Dr. Kenneth Kendler, a psychiatrist at the Medical College of Virginia in Richmond, Va., who led the study.
That makes the genetic influence in alcoholism among women about the same as for hypertension, and somewhat higher than that estimated for coronary artery disease, stroke or major depression.
"It's a very important finding, showing that heritability for alcoholism in women is so high," said Dr. Robert Cloninger, a psychiatrist at Washington University who is director of a multi-site study of genetics and alcoholism for the National Institute on Alcohol Abuse and Alcoholism.
The study challenges what had been conventional wisdom among physicians and psychotherapists: that social and psychological forces were far stronger among women than genetics in the steps leading to alcoholism.
In their research, Kendler and colleagues studied 1,080 adult pairs of female twins born in Virginia. Each twin was interviewed by a clinical social worker to determine whether she had ever been dependent on alcohol.
Research found that at every level of alcoholism, identical twins, who are genetic carbon copies of each other, were significantly more likely than fraternal twins to have similar histories of alcoholism, suggesting a genetic role.
There are many ways that genes might make a person susceptible to alcoholism.
"One possibility," Kendler said, "is that genes may make a person more vulnerable to moods like depression or anxiety, and they may try to soothe themselves by drinking. Some genes may affect how your liver metabolizes alcohol, while others determine how pleasurable you find it."