An open naltrexone treatment study in pathological gambling disorder

The present study was designed to test the short-term efficacy and safety of naltrexone in the treatment of pathological gambling disorder. Seventeen subjects (seven men, 10 women) who fulfilled DSM-IV criteria for pathological gambling disorder, and were free from other Axis I diagnoses by Structured Clinical Interview for DSM-III-R screening, participated in a 6-week open naltrexone flexible dose trial. Gambling symptom change was assessed with the patient-rated Clinical Global Impression (CGI) Scale, the clinician-rated CGI and the Gambling Symptom Assessment Scale. Side-effects were monitored weekly and liver function tests biweekly. Naltrexone reduced urges to gamble and gambling behaviour. The mean change in gambling frequency per week was 1.40 +/- 0.28 episodes per week; the mean change in dollars lost per week was $66.95 +/- 13.77; and the mean change in clinician-rated CGI Improvement was 0.40 +/- 0.04. Of those who responded to the medication, the majority had done so by the end of the fourth week. Men responded to naltrexone as well as women. The average naltrexone dose required for effective symptom control was 157 mg/day. Nausea was common during the first week (47%). The present findings provide evidence that naltrexone may be effective in the treatment of pathological gambling disorder. The present report is preliminary and controlled trials are needed to confirm these findings.