Olanzapine in the Treatment of Pathological Gambling: A Negative Randomized Placebo-Controlled Trial.

Author(s): McElroy SL, Nelson EB, Welge JA, Kaehler L, Keck PE

Affiliation(s): From the Psychopharmacology Research Program, Department of Psychiatry, University of Cincinnati College of Medicine (Drs. McElroy, Nelson, Welge, and Keck and Ms. Kaehler) and Mental Health Service Line and General Clinical Research Center, Cincinnati Veterans Affairs Medical Center (Dr. Keck), Cincinnati, Ohio.

Publication date & source: 2008-01-30, J Clin Psychiatry., :e1-e8 [Epub ahead of print]

Publication type:

OBJECTIVE: Pathological gambling is associated with bipolar disorder and dopamine dysfunction. Olanzapine is a second-generation antipsychotic with mood-stabilizing properties and antagonistic activity at several dopamine receptors. The purpose of this study was to evaluate olanzapine in the treatment of pathological gambling. METHOD: In this 12-week, single-center, randomized, double-blind, placebo-controlled, flexible-dose (2.5-15 mg/day) trial, 42 outpatients with pathological gambling by DSM-IV-TR criteria received olanzapine (N = 21) or placebo (N = 21). The primary outcome measure was the Pathological Gambling Adaptation of the Yale-Brown Obsessive Compulsive Scale (PG-YBOCS). The primary analysis of efficacy was a longitudinal analysis of the intent-to-treat sample, with treatment-by-time interaction as the effect measure. Subjects were enrolled from June 2, 2000, through November 28, 2005. RESULTS: Compared with placebo, olanzapine was associated with a similar rate of reduction in total scores on the PG-YBOCS scale, as well as in gambling episodes/week, hours gambled/week, and Clinical Global Impressions-Severity of Illness scale scores. The mean (SD) olanzapine daily dose at endpoint evaluation was 8.9 (5.2) mg/day. Eleven subjects (52%) receiving olanzapine and 6 (29%) receiving placebo discontinued prematurely; 3 subjects receiving olanzapine and 2 receiving placebo discontinued because of adverse events. Events causing olanzapine discontinuation were pneumonia, sedation, and hypomania. CONCLUSION: Olanzapine was not superior to placebo in the short-term treatment of pathological gambling. It was also associated with a high discontinuation rate. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00438776 (http://www.clinicaltrials.gov).