An MGH psychiatry researcher has found that gambling activates the brain in a way very similar to drug abuse, a discovery that has implications for how compulsive gamblers are treated.
Tensions are rising at the Massachusetts State House over Governor Deval Patrick’s plan to license three resort casinos. Opponents of the measure question whether the promises of increased revenue and jobs are worth the social costs associated with a potential rise in pathological gambling. A House committee is expected to vote on the measure later today before sending it to the full House.
It is estimated that 4 percent to 6 percent of those who gamble repeatedly will become pathological gamblers, according to the Massachusetts Council on Compulsive Gambling. (For comparison, 6 percent of those who drink develop alcoholism.) But until recently, there has been little research on the biological causes of compulsive gambling.
“It’s critical to understand the biological variables [of pathological gambling] so that policy makers can start to figure out what environmental controls—the only variables we have direct control over—would be appropriate,” says psychiatry researcher Hans Breiter of Massachusetts General Hospital.
Research on the biology of pathological gambling is so new that the American Psychological Association does not currently classify compulsive gambling as a biological addiction like alcohol or drug abuse, but instead considers it an “impulse control disorder.”
But brain-imaging studies from Breiter’s lab have recently shown that pathological gambling taps into the same neural circuits as cocaine addiction. If more studies from Breiter’s lab and others confirm that gambling can be biologically addictive like substance abuse, clinicians’ level of awareness will be greatly increased, allowing patients to take fuller advantage of existing infrastructure and services for substance-abuse treatment, says Breiter.
Functional magnetic resonance imaging of the brains of healthy subjects anticipating winning a game of roulette (top) and drug addicts anticipating receiving a small dose of cocaine (bottom) reveal similar activity in the nucleus accumbens, a key reward structure in the brain that has been implicated in addiction. (Credit: Hans Breiter, MGH)
Chasing the “rush”
Early in his career, Breiter began mapping the brain circuitry of motivation and reward in humans, which is hijacked by addiction. These circuits evolved to reward behaviors critical to survival, such as eating and sex, with feelings of euphoria and arousal. Addicts continually pursue this arousal feeling, or “rush,” which is triggered by the release of the neurotransmitter dopamine. All addictive drugs so far studied act by either directly or indirectly increasing levels of dopamine in a critical center of the brain’s reward pathway, the nucleus accumbens.
Breiter and his colleagues have found that gambling appears to act similarly on the brain. Using functional magnetic resonance imaging, Breiter scanned the brains of healthy people who were anticipating winning a game of chance, which resembled roulette. He found elevated activity in the nucleus accumbens similar to what he had seen in a previous study in which he had scanned the brains of addicts anticipating moderate doses of cocaine. He even mixed up the gambling and the cocaine study scans and, without knowing which study each scan came from, found they were so similar that he could not tell the difference.
Breiter’s brain-imaging work is “superb,” says Antoine Bechara, a professor of psychology at the University of Southern California who studies the neural basis of decision making in health and addiction. “It confirms at the neural level that money, at the end, activates the same neural processes that are engaged in reward in general, be it drugs or natural rewards.”
Bechara adds that money may represent a special kind of reward in our culture, capable of eliciting strong automatic visceral reactions, because it can buy “the best of natural rewards.”
With Breiter’s study, and those that have followed from other labs, there’s now plenty of evidence that gambling, like psychoactive substances such as cocaine or alcohol, can be addictive at a biological level, and that pathological gambling should be reclassified as an addiction, says Bob Breen, the director of the Rhode Island Gambling Treatment Program at the Rhode Island Hospital. In fact, Breen says he and other clinical psychologists are already successfully using addiction treatment models with pathological gamblers. Such a reclassification, he adds, may lead to an increase in funding for research and treatment for gambling addicts.
Beyond the brain
Both Breiter and Breen point out that the roots of pathological gambling aren’t all biological; environmental factors play a role as well. For instance, the quality of family life, the proximity to casinos or other gambling facilities, the types of gambling involved (fast-moving, repetitive slot machines tend to be more addictive than slower, more socially interactive table games), and the level of education in the mathematics of gambling odds may also influence if and how compulsive gambling comes about.
Altogether, Breiter says that policy makers should take into account both the biological and environmental factors involved in pathological gambling when making decisions about whether to allow casinos. Otherwise, says Breiter, "they’re playing with fire, because there’s a slippery slope between normal and addictive behavior.”