A double-blind, placebo-controlled trial of topiramate for pathological gambling

Abstract

Objectives. Pathological gambling (PG) is an impulse control disorder characterized by recurrent gambling thoughts and behaviours that impair social functioning. Earlier studies suggested that topiramate may be effective in treating some impulse control disorders. We conducted the first randomized, controlled trial of topiramate in PG. Methods. PG patients were randomized to topiramate (N = 20) or placebo (N = 22) in this 14-week, double-blind, placebo-controlled, parallel-group trial. The primary outcome measure was change in the obsessions subscale of the Yale-Brown Obsessive-Compulsive Scale Modified for Pathological Gambling. Results. Mixed regression models (time [weeks] × treatment) revealed no significant treatment effect of topiramate on the primary or secondary outcome measures. The most statistically robust findings involved reducing the Barratt Impulsiveness Scale (BIS) total score and Motor and Non-Planning subscale scores, for which topiramate outperformed placebo at merely a trend level (P < 0.1). Conclusions. The observed trend in BIS score reductions may warrant further investigation to study whether topiramate reduces clinically important impulsivity in PG. Treatment studies with larger samples and less stringent exclusion criteria are needed to produce results that can be generalized to pathological gamblers in the community.

Key words::

• pathological gambling
• topiramate
• impulsivity
• impulse control disorder
• placebo-controlled

Acknowledgements

This study was funded by Ortho-McNeil Janssen Scientific Affairs, LLC. Shishuka Malhotra, MD, at Neuro Behavioral Clinical Research, Inc., Canton, OH, enrolled nine subjects. Bill Chaplin, PhD, conducted the statistical analysis. Holly Hamilton, BA, and James Fisher, BA, assisted with manuscript preparation.

Statement of Interest

Heather Berlin, PhD, MPH, Stefano Pallanti, MD, PhD, Daphne Simeon, MD, and Ashley Braun, BA, have no potential conflicts of interest. Lorrin Koran, MD's, potential conflicts of interest relevant to the time frame of the paper were Forest Pharmaceuticals, Speakers’ Bureau; Eli Lilly, research grant; Sepracor, research grant; and Jazz Pharmaceuticals, Consultant. Eric Hollander, MD, has consulted and received research grants from Ortho-McNeil, Abbott, and Solvay. Timothy Fong, MD, received research support from Ortho McNeil, NIDA (K23 Career Development Award) and the Annenberg Foundation, and participated in the Speaker's Bureaus of with Pfizer, Eli Lilly and Reckitt-Benckiser. Susan McElroy, MD, is a consultant to or member of the scientific advisory boards of Eli Lilly, Ortho-McNeil (during the time the study was conducted), and Schering-Plough. She is a principal or co-investigator on studies sponsored by the above companies and Abbott, AstraZeneca, Bristol-Myers Squibb, Cephalon, Forest, GlaxoSmithKline, Jazz, Marriott Foundation, National Institute of Mental Health, OREXIGEN, Shire, and Takeda Pharmaceutical Company Ltd. She is also an inventor on United States Patent No. 6,323,236 B2, Use of Sulfamate Derivatives for Treating Impulse Control Disorders, and along with the patent's assignee, University of Cincinnati, Cincinnati, Ohio, has received payments from Johnson & Johnson, which has exclusive rights under the patent. Marc N. Potenza, MD, PhD, has consulted for Boehringer Ingelheim; has financial interests in Somaxon; has received research support from the National Institutes of Health, Veteran's Administration, Mohegan Sun Casino, and Forest Laboratories, Ortho-McNeil, Oy-Control/Biotie and Glaxo-SmithKline pharmaceuticals; has participated in surveys, mailings or telephone consultations related to drug addiction, impulse control disorders or other health topics; has consulted for law offices and the federal public defender's office in issues related to impulse control disorders; has performed grant reviews for the National Institutes of Health and other agencies; has given academic lectures in grand rounds, CME events and other clinical or scientific venues; has generated books or book chapters for publishers of mental health texts; has edited for journals; and has provided clinical care in the Connecticut Department of Mental Health and Addiction Services Problem Gambling Services Program. Dr. Potenza's involvement was also supported by a Center of Excellence in Gambling Research grant from the National Center for Responsible Gaming and its Institute for Research on Gambling Disorders. The contents of the manuscript are solely the responsibility of the authors and do not necessarily represent the official views of the National Center for Responsible Gaming or the Institute for Research on Gambling Disorders or any of the other funding agencies.