Drug Treatment for Pathologic Gambling Disorder

PGD is a prominent and growing social problem. Unfortunately, there is no established drug
treatment for this disorder. Preliminary investigations demonstrate that naltrexone in doses
up to 250 mg/day is well tolerated and safe during an 11-week period and may be a viable
treatment option for PGD patients with severe urges. The implications of this study extend
from PGD to other impulse control disorders, including compulsive shopping, kleptomania, and
possibly alcoholism.

Participants are randomly assigned to receive either naltrexone or placebo for 16 weeks. The
responses of men and women are compared to determine whether efficacy is distributed in a
male:female ratio analogous to that of the PGD population in the United States. A Clinical
Global Impression and a Gambling Symptom Scale are used to assess participants.

Inclusion Criteria:

- Diagnostic and Statistical Manual IV criteria for Pathological Gambling Disorder

- Moderate or severe gambling urge assessed by the Gambling Symptom Assessment Scale

- No psychiatric drug use for 2 weeks or more

- Score >= 5 on The South Oaks Gambling Screen

- Hamilton Depression Rating Scale and Anxiety Rating score < 26. An increase (up to 10
points) of the scores is allowed unless the subject shows the risks of suicide.

- Completion of complete blood count, urinalysis, liver and thyroid function tests, and
pregnancy tests, with no evidence of significant lab abnormalities

- Reliable birth control in women of child-bearing potential