N-Acetyl Cysteine, a Glutamate-Modulating Agent, in the Treatment of Pathological Gambling: A Pilot Study
Received 12 October 2006; received in revised form 7 November 2006; accepted 23 November 2006. published online 24 April 2007.
Background
Although pathological gambling (PG) is relatively common, pharmacotherapy research for PG is limited. N-acetyl cysteine (NAC), an amino acid, seems to restore extracellular glutamate concentration in the nucleus accumbens and therefore offers promise in reducing addictive behavior.
Methods
Twenty-seven subjects (12 women) with DSM-IV PG were treated in an 8-week open-label trial of NAC with responders (defined as a ≥ 30% reduction in Yale Brown Obsessive Compulsive Scale Modified for Pathological Gambling [PG-YBOCS] total score at end point) randomized to 6 weeks of double-blind NAC or placebo.
Results
The PG-YBOCS scores decreased from a mean of 20.3 ± 4.1 at baseline to 11.8 ± 9.8 at the end of the open-label phase (p < .001). Sixteen of 27 subjects (59.3%) met responder criteria. The mean effective dose of NAC was 1476.9 ± 311.3 mg/day. Of 16 responders, 13 entered the double-blind phase. Of those assigned to NAC, 83.3% still met responder criteria at the end of the double-blind phase, compared with only 28.6% of those assigned to placebo.
Conclusions
The efficacy of NAC lends support to the hypothesis that pharmacological manipulation of the glutamate system might target core symptoms of reward-seeking addictive behaviors such as gambling. Larger, longer, placebo-controlled double-blind studies are warranted.
Department of Psychiatry University of Minnesota School of Medicine, Minneapolis, Minnesota.
Address reprint requests to Jon E. Grant, J.D., M.D., M.P.H., Department of Psychiatry, University of Minnesota School of Medicine, 2450 Riverside Avenue, Minneapolis, MN 55454
ABSTRACT