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Gambling and Your Genes

Aug. 2, 2000 -- Why can some people occasionally buy a lottery ticket or play a slot machine and suffer no ill effects beyond losing a few bucks, while others become so gambling obsessed that they risk their savings, their jobs, and their relationships with loved ones?

One answer may lie in our genes, according to two new studies focusing on compulsive gambling.

"Our study suggests that there are genetic factors that increase the probability of developing gambling problems," Wendy Slutske, PhD, a professor in the psychology department at the University of Missouri, tells WebMD. What's more, she says, "some of these genetic factors appear to be the same as those that increase the probability of developing alcohol dependence."

Slutske, whose study was published in the Archives of General Psychiatry, says many researchers think people with gambling problems become dependent on the euphoria they get from gambling, which may be similar to the high achieved by alcohol or drugs. For this reason, some classify gambling as an addictive disorder, like alcohol and drug abuse.

Gambling is considered pathological when it seriously disrupts the gambler's life. The problem is thought to affect somewhere between 1.5% to 11% of the adult population. And the rate of suicide attempts among problem gamblers is very high, with as many as 24% of the gamblers who seek treatment reporting such attempts.

Much more is known about the causes of alcoholism then of gambling problems. Still, research shows that 19% to 50% of people who are treated for problem gambling also have a history of alcohol abuse or dependence. This suggests there may be a common vulnerability underlying problem gambling and other addictive disorders such as alcoholism.

To test the link between gambling and substance abuse, Slutske and colleagues conducted phone interviews with participants in The Vietnam Era Twin Study (VETS). VETS is a group of more than 8,000 members of sets of male twins, some identical and some fraternal, all of whom served in the U.S. military from 1965 to 1975.

Symptoms of problem gambling were evaluated only among those participants who had ever gambled, bet, bought a lottery ticket, or who used a slot machine 25 or more times in a year. Based on the answers over the phone, and using several evaluation tools to filter out the effects of the twins' shared environments and other factors, researchers found that the risk of problem gambling had a strong genetic component. They also found a strong genetic component for alcohol dependence and a link between alcohol dependence and problem gambling.

The researchers also speculate that part of the link between problem gambling and alcohol dependence may be related to the fact that these two addictions feed off each other. They note that many gambling facilities provide free alcohol to customers, and that studies have shown many problem gamblers drink while gambling.