Problem Gambling in Genes

(Reuters Health) - Odds are good that if one of your parents is addicted to gambling, you might be too, a new study of Australian twins concludes.

"Previous research in men showed that gambling addiction can run in the family," study co-author Wendy Slutske, of the University of Missouri, told Reuters Health. "This study extends those finding to include women."

Scientists have found that genes play a role in a number of addictions, the study authors note in the June issue of the Archives of General Psychiatry.

By studying identical (identical genetic makeup) and fraternal (some shared genes) twins, Slutske and colleagues from Australia's Queensland Institute of Medical Research in Brisbane were able to tease out the different impacts of genetic and environmental factors on addiction.

The team asked more than 2,700 women and 2,000 men from the Australian Twin Registry questions about their gambling, and also questioned their friends.

Almost all the study members gambled some, but the men were twice as likely as women to be gambling addicts. Thirty-four of the women (about one percent) met five or more of the criteria for problem gambling, compared with 70 of the men (about three percent).

These differences may be explained by social or environmental influences, since as the authors point out, gambling addiction is five times more common in Australia than in the U.S.

Slutske and her colleagues found that "if your twin has a gambling problem, you're more likely to develop one too if you're an identical twin than if you're a fraternal twin," she said. That suggested that shared genes play a role.

The authors conclude that, in line with decades of genetic research, "shared environmental factors do not explain" variations in addictive behaviors.

That's not to say environment plays no role, they argue. "A perfect storm" of gambling addiction might occur for the biological child of a gambling addict who is "exposed to a problem gambling role model and inherits problem gambling susceptibility genes," they write.

Even though the research suggests genes play a role in addictive gambling, there's probably no "gambling gene," Slutske told Reuters Health.

"Like alcoholism, problem gambling is a complex disorder," Slutske said. "The answer will be in a collection of genes, maybe 10 or 100, we don't know how many, but each gene will increase the risk slightly for developing those problems."