Researchers from Yale University have found new evidence for a link between obsessive compulsive spectrum disorder and aperathological gambling, perhaps due to genetic factors.

Building off of previous research that suggested a link between addictive behavior and pathological gambling, this study is part of an ongoing effort to further classify gambling addiction on an impulse-to-compulsion spectrum. The central question of the debate is: To what extent do pathological gamblers have impulse-control problems as opposed to a compulsion to gamble? This study adds evidence that there is an element of compulsive behavior for some pathological gamblers.

“We were trying to understand the relation between pathological gambling and other disorders,” said Yale professor of psychiatry at the School of Medicine and the paper’s senior author Marc Potenza. “There has been some debate in the literature about how best to consider pathological gambling — whether it might fall along the impulsive-compulsive spectrum or be thought of as an addiction without the drug.”

The researchers performed a twin study, using the Vietnam Era Twin Registry — a compiled list of male twin veterans of the Vietnam War — to study both genetic explanations of pathological gambling and its connection with latent obsessive-compulsive behavior. Twin studies allow researchers to better disentangle the complex relationship between environmental and genetic factors at play in disorders, diseases and behaviors. The researchers found a correlation between latent obsessive-compulsive behavior and pathological gambling. In addition, they found behavioral correlations between twins, suggesting a genetic component to compulsive behavior and pathological gambling.

It was unusual that the researchers decided to use a twin study, as opposed to conducting genetic testing, Potenza said. The methodology allowed the researchers to ascertain a genetic component, but without the genetic testing, they were unable to identify which genes cause this effect. That second question, Potenza said, may lead to further research.

But clinical professor at the Stanford School of Medicine Alan Ringold, an expert on OCD who is unaffiliated with the study, said he does not believe pathological gambling is related to OCD, which is an extreme enough form of obsessive behavior that it is classified as a disorder in the Diagnostic and Statistical Manual, which classifies psychiatric disorders.

“Gambling is an impulse control disorder. It’s not OCD,” Ringold said, highlighting the controversy within the medical community about whether gambling is compulsion-based or impulse control-based.

Because the researchers only used male participants, it is unknown to what extent the results generalize to the entire population.

“This is an example of being persistent,” said Jeffrey Scherrer, professor in the department of family and community medicine at Saint Louis University School of Medicine. “This gambling study data collection was completed around 2003, and we began some preliminary analysis. We weren’t able to get back together on this until many years later, so the lesson is don’t give up on an idea.”

Between 5 and 7 percent of Americans have a problem with gambling.