A randomized double-blind fluvoxamine/placebo crossover trial in pathologic gambling

Background: The study assessed the efficacy and tolerability of the selecti ve serotonin reuptake inhibitor (SSRI) fluvoxamine in the treatment of path ologic gambling (PG). Methods: A 16-week randomized double-blind crossover design insured that ea ch subject received 8 weeks of fluvoxamine and 8 weeks of a placebo. Fiftee n patients entered and 10 subjects, all male, completed the study. Results: Fluvoxamine resulted in a significantly greater percent improvemen t in overall gambling severity on the PG Clinical Global Impression (PG-CGI ) scale. There was a significant drug effect on gambling urge and behavior as measured by the PG modification of the Yale-Brown Obsessive Compulsive S cale and PG-CGI scale improvement scores; however, there was a significant interaction of drug effect with the order of administration of drug and pla cebo. Post hoc analysis, treating each phase as a separate trial, demonstra ted a significant difference between fluvoxamine and the placebo in the sec ond phase of the trial but not in the first. Fluvoxamine side effects were of only mild intensity and consistent with SSRI treatment and were not asso ciated with early withdrawal from the study. Conclusions: These findings suggest that fluvoxamine is well tolerated and may be effective in the treatment of PG in an acute trial, and that an earl y placebo effect in PG treatment appears to diminish over time. To confirm this finding and to determine whether improvement persists over an extended period of time, a longer duration parallel-design trial with long-term mai ntenance follow-up should be conducted in a larger and more diverse PG popu lation. Biol Psychiatry 2000;47:813-817 (C) 2000 Society of Biological Psyc hiatry.