More threads by David Baxter PhD

David Baxter PhD

Late Founder
Commonly Used Diet Supplement Reduces Gambling Urges
Wednesday, September 12, 2007

As the die roll across the table, tantalizing spectators with brief visions of fortune or bankruptcy, excitement fills the air. For some, this excitement is a pleasant diversion but something that they can easily walk away from when they can no longer afford to wager. However, as many as 3.4% of adults cannot just walk away. Even if they do manage to leave the casino, thoughts of gambling hound them. While therapy has been the traditional approach to controlling these impulses, the psychopharmacological approach has been the subject of much investigation in recent years. Until now, almost all of the drugs tested for gambling treatment had unpredictable side-effects or unconvincing evidentiary support, but a simple amino acid was recently shown to be highly effective in a small study from the University of Minnesota.

In 2004, the UCLA Gambling Studies Program presented a useful review of the state of research on gambling medication. The review outlines the investigation into the effectiveness of SSRIs, opioid antagonists, and mood stabilizers. Dr. Hollander was the first to set up a double-blind placebo study of an SSRI used on gamblers. He found that 67% of those on fluvoxamine improved, while only 25% of those on the placebo reported a lessening of symptoms. However, Blanco, Petkova, Ibanez and Saiz-Ruiz were unable to find this benefit when performing their own study over a longer time period.

The opioid antagonist naltrexone showed impressive results in a 2001 experiment by Kim, Grant, Adson and Shin, but it came with greater side effects than the SSRIs. Patients commonly experienced nausea, and there is some concern that the high doses necessary to block the gambling impulse may damage the liver.

Even though they've been happening since the time of the DSM-III, experiments with mood stabilizers are still inconclusive. Dr. Moskowitz published anecdotal evidence of three amazing successes in the article, "Lithium and Lady Luck." This older research was never sufficiently followed-up on, and these drugs have yet to receive the clear support of large double-blind studies. While there is some encouraging evidence that mood stabilizers work, many of the positive studies included patients with bipolar disorder, leaving open the possibility that the drugs do nothing to specifically target the problem of gambling.

None of the drug options discussed above are perfectly safe and proven, so a study from the University of Minnesota appearing this week in Biological Psychiatry was received with enthusiasm. N-acetyl cysteine (NAC), the amino acid used in this experiment, is used in common dietary supplements and couch medicines administered without prescription. NAC regulates glutamate, a versatile neurotransmitter that has an impact on learning, memory, and reward systems. Dr. Jon Grant, lead author of the study, was encouraged to perform this most recent experiment when more than half of the 27 subjects in his pilot study showed some response to NAC. He enrolled those responders in a double-blind study and found that 83.3% improved with NAC as opposed to 28.6% with the placebo.

Dr. Grant's study is not free of the uncertainties of previous gambling drug studies. The group that both qualified for and agreed to participate in the final study was small, only 13 people, and this group was pre-selected to be responsive. Larger studies are certainly required before large conclusions can be made, but we can safely say that NAC positively affects a subset of gamblers. It is possible that the diagnosis of pathological gambling encompasses a variety of underlying problems and drug susceptibilities. If that is true, then the introduction of new drugs like glutamate regulators will be a valuable addition to the psychiatrist's necessarily diverse repertoire even if they do not turn out to be superior in all cases to previously-discovered drugs.
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