Paroxetine treatment of pathological gambling: a multi-centre randomized controlled trial

Abstract

Previous studies have suggested the efficacy of serotonergic agents in the treatment of pathological gambling. The aim of the present study was to determine whether treatment with paroxetine in a large sample of subjects with pathological gambling would effectively diminish the severity of gambling symptoms. A 16-week, double-blind, placebo-controlled trial was conducted at five outpatient academic research centres in two countries (USA and Spain). Seventy-six outpatients (mean age 45.4+/-10.6 years; 30 women, 46 men) with pathological gambling were randomized to acute treatment with paroxetine in flexible daily dosages of 10-60 mg/day (n=36) or placebo (n=40). The primary outcome measure was the Clinical Global Impressions scale. Both the paroxetine- and the placebo-treated groups demonstrated comparable improvement at 16 weeks (59% response rate in the paroxetine group, 49% rate in the placebo group; chi squared=0.737; d.f.=1; P=0.390). Paroxetine consistently resulted in a greater percentage of responders at each study visit compared to placebo but failed to demonstrate statistical superiority to placebo on scores on the Clinical Global Impressions scale, the Yale-Brown Obsessive-Compulsive Scale Modified for Pathological Gambling, or the Gambling Symptom Assessment Scale. High rates of symptom improvement were observed in pathological gamblers receiving either paroxetine or placebo after 16 weeks. Paroxetine consistently demonstrated an advantage over placebo on the Clinical Global Impressions scale; however, a larger sample size may have registered significant differences.

Assessing and Treating Problem Gambling: Empirical Status and Promising Trends

“…Paroxetine was found to be more effective at the end of treatment, as evaluated by rating scales. There were no significant group differences at the end of treatment in a second study of paroxetine's efficacy (a 16-week, double-blind, placebocontrolled study), according to investigator ratings of clinical improvement and other measures (71).…”

“…Recent years have witnessed proliferating research evaluating the efficacy of a wide variety of medications used to treat problem gambling, although to date no medication has been approved for treatment of this disorder. Grant and others have recently reviewed the evidence of pharmacotherapy for problem gambling and summarized the key issues in this area of research (71). Below, we summarize the few studies that have employed double-blind, placebo-controlled, and randomization methodology.…”

Compulsive Aspects of Impulse-Control Disorders

“…Data from double-blinded, randomized pharmacotherapy trials of SRIs in the treatment of PG, have been inconclusive, however [7], with medication showing a significant advantage over placebo in some but not in other trials of SRIs [26][27][28][29].…”

The Evidence Base Supporting the Subtyping of Gamblers in Treatment

“…A high placebo response rate has been reported in pharmacological treatment studies on pathological gambling (Rugle, Derevensky, Gupta, Winters, & Stinchfield, 2001). In two studies (Grant et al, 2003;Saiz-Ruiz et al, 2005), the duration and rate of placebo response, 49% at 16 weeks and 72% at 6 months, respectively, is unusually long in duration and high in response rate. The largest multisite pharmacological study on pathological gamblers (Grant et al, 2003) was a failure because of lack of separation between placebo and the active medication.…”