Naltrexone, a drug frequently prescribed for the treatment of alcoholism and drug dependence, was seen to diminish the urge to gamble in a US study of pathological gamblers.

Nearly 40 percent of the pathological gamblers who took the drug were able to abstain from all gambling for at least one month. Similar abstention occurred among just 10.5 percent of those treated with an inactive placebo, Dr. Jon E. Grant of the University of Minnesota in Minneapolis and colleagues report in the Journal of Clinical Psychiatry.

Study subjects included people aged 14 to 59 years old who gambled for six to 32 hours each week and met clinical criteria for pathological gambling. A majority of the study group reported symptoms of depression and about one-fifth said they had anxiety disorder, but none currently had bipolar, psychotic, or substance abuse disorders.

The investigators randomly assigned 58 men and women to take 50, 100, or 150 milligrams of naltrexone daily, for up to 18 weeks. Another 19 individuals took a placebo.

Subjects who got naltrexone were much more likely to abstain from gambling than those who got the placebo. Moreover, low doses of naltrexone were as effective as higher doses.

Those treated with naltrexone, compared with the placebo, reported fewer gambling urges and thoughts, and indicated they were better able to resist their urges to gamble. These findings held in analyses of the entire study group, the 49 individuals who completed the study, and in comparisons between men and women.

The investigators conclude that naltrexone is safe and well-tolerated for as long as four to five months, and helps control symptoms of pathological gambling.

(Agencies via Xinhua News Agency June 6, 2008)