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Defining compulsive gambling is like defining compulsive drinking: it's not clear when you cross the line. But if there are enough signs that your behavior is starting to slip out of your control (see the self-test), chances are that you have a problem. It's a problem of special interest to researchers because it reveals a lot about addiction as a whole. One of the difficulties in understanding drug or alcohol abuse is that the minute you add a chemical to the body, you muddy the mental processes. "It's hard to tease the connection out because you don't know how much is the drug and how much is the behavior," says Whyte. "But gambling is a pure addiction."
To see if that's true, scientists turn to such advanced diagnostic tools as functional magnetic resonance imaging (fMRI) machines to peer into the brains of gamblers while they play. In a 2001 study conducted at Harvard Medical School and elsewhere, researchers monitored subjects as they engaged in a wheel-of-fortune game. The investigators looked mainly at several areas of the brain known to be involved in processing dopamine, a pleasure-inducing chemical released during drug and alcohol use.
Sure enough, the same areas lighted up when test subjects gambled, becoming active not only when they won but also when they merely expected to win--precisely the pattern of anticipation and reward that drug and alcohol users show. "This put gambling on the map with other neurobiologic addictions," says Dr. Barry Kosofsky, a pediatric neurologist at Weill Cornell Medical Center in New York City.
Surprising support for that work came earlier this month when researchers at Minnesota's Mayo Clinic reported that 11 Parkinson's disease patients being treated with dopamine-enhancing medications began gambling compulsively; one patient eventually lost $100,000. Six of the 11 also began engaging in compulsive eating, drinking, spending or sex. Only when the dopamine was discontinued did the patients return to normal.
The dopamine cycle may not be the only thing that drives gamblers. Personality also plays a part. This month researchers in the U.S., Britain and New Zealand released the latest results from an ongoing, 30-year study of roughly 1,000 children born in the early 1970s. One purpose of the research was to determine which temperament types were most likely to lead to addictions.
The just released results showed that compulsive gamblers, drinkers and drug users have high underlying levels of negative emotionality, a syndrome that includes nervousness, anger and a tendency to worry and feel victimized. Significantly, they also score lower in the so-called constraint category, meaning they are given to impulsiveness and thrill seeking. That's a bad combination, particularly when you throw drugs, drink or gambling into the mix. "It's like picking your poison," says psychologist Avshalom Caspi of King's College in London, one of the researchers in the study.