Genetic influences play important role in development of gambling disorders: Report

Genetic influences appear important in the development of gambling disorders in both women and men, according to a report in the June issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Pathological gambling is known to run in families, according to background information in the article. In one study, 8 percent of the first-degree relatives of individuals with gambling disorders had a lifetime history of similar problems, compared with 2 percent of relatives of unaffected individuals. Almost half of the individuals in treatment for pathological gambling are women.

To investigate potential genetic and environmental risk factors for development of disordered gambling, Wendy S. Slutske, Ph.D., of University of Missouri-Columbia, and colleagues studied 4,764 individuals from 2,889 Australian twin pairs (age 32 to 43 years, 57 percent women). The twins were assessed through structured telephone interviews for disordered gambling and similarity of their childhood environment.

Many of the participants were frequent gamblers; almost all of them had ever gambled, about one-half had gambled at least once a month and about one-third had gambled at least once a week. A total of 2.2 percent of the participants met criteria for pathological gambling, including 3.4 percent of men and 1.2 percent of women; 12.5 percent had ever experienced one or more symptoms of pathological gambling (18.2 percent of men and 8.3 percent of women).

"The estimate of the proportion of variation in liability for disordered gambling due to genetic influences was 49.2 percent," the authors write. "There was no evidence for shared environmental influences contributing to variation in disordered gambling liability." There was also no evidence of sex differences in the causes of pathological gambling.

"This study represents a major step forward in that it establishes for the first time that genes are as important in the etiology of disordered gambling in women as they are in men," the authors write. "In addition to similar relative contributions of genetic vs. environmental factors to variation in liability for disordered gambling, the results suggest that the susceptibility genes contributing to variation in liability for disordered gambling may also overlap considerably in men and women."

"The discovery of the specific genes and environments involved in the development of disordered gambling remains an important direction for future research," they conclude.