Medicine to curb gambling looks like a good bet

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Mike Ambrose, a computer-systems analyst, often would spend 36 hours straight on weekends playing slot machines until his paycheck was gone.

After blowing $15,000 to $20,000 a year on his habit for more than a decade, Ambrose, in desperation, volunteered as a patient in a clinical study to test a drug to control his gambling urge.

The medication, naltrexone, originally devised to combat heroin addiction and alcoholism, changed his life. Within two weeks, the Fridley, Minn., man noticed a "tremendous difference - suddenly, the urges stopped."

Three years later, Ambrose, 60, still takes a maintenance dose of the drug. "Naltrexone takes all the excitement out of it, and I don't get the rush anymore," he said.

The final results of this study conducted at the University of Minnesota were reported earlier this month in the journal Biological Psychiatry. The study found that people who took naltrexone reported that their gambling urges - once so powerful that they stole from their children and even turned to prostitution to pay gambling debts - either vanished or were diminished enough that they could resist temptation.

Brain malfunction

The Minnesota research is among a handful of recent studies suggesting that the gambling urge has its roots in biology, rather than human frailty.

Researchers say that gambling may be, at least in part, sparked by a short circuit in the brain's wiring or an imbalance in key brain chemicals. And drugs such as naltrexone, which blocks the brain's pleasure pathways, are helping people control their impulses.

The findings offer new hope to the estimated 1 percent to 3 percent of the population that suffers from a gambling addiction, for which there is no standard treatment.

The University of Minnesota experiment, for example, involved 45 compulsive gamblers. For 11 weeks, 20 people received naltrexone, which dulls the sensation of pleasure that is associated with addictive cravings. The remainder were given a placebo, or dummy pill.

Each week, participants were interviewed about the severity of their symptoms, the frequency and duration of their urges, the time they were consumed with thoughts about gambling and the time they actually spent gambling.

Three-quarters of those on the medication reported substantial relief from the compulsion that had seriously disrupted their lives, contrasted with only one-fourth of the placebo group.

'The data shocked us'

"Their symptoms are under control, so they can have a normal life," says Dr. Suck Won Kim, a psychiatrist at the University of Minnesota Medical School in Minneapolis and co-author of the study. "The data shocked us. We got fantastic results."

Researchers studying gambling behavior at Rhode Island Hospital in Providence reported similar findings with another drug, Celexa, or citalopram, a type of antidepressant known as an SSRI. The study was, however, relatively small, involving just 15 compulsive gamblers, and lasted for just 12 weeks. (The study was funded by Forest Laboratories, which markets Celexa.)

Previous studies have suggested that people with obsessive-compulsive behavior disorders, such as pathological gambling, suffer from a deficiency of serotonin, a brain chemical that may be involved in the ability to delay or prevent acting on impulses.

The class of drugs known as SSRIs (or serotonin reuptake inhibitors) prevent serotonin from being removed from the synapses in the brain.

In the Rhode Island research, 13 of the 15 study participants reported significant improvements in all gambling measures, including the number of days gambled and their preoccupation with gambling.

The amount of money participants lost dropped from an average of $1,900 in the two weeks before the study to $145 in the final two weeks.

"Individuals who are struggling to get a handle on this devastating problem should be aware of the possible treatment options," said Dr. Mark Zimmerman, director of outpatient psychiatry at Rhode Island Hospital and the study's lead author.

The Food and Drug Administration has not yet approved these medications for use in curbing gambling urges. Still, these studies suggest that medications that compensate for deficits in brain chemistry may hold the key to controlling impulses.