Effect of a tricyclic antidepressant and opiate antagonist on binge-eating behavior in normoweight bulimic and obese, binge-eating subjects. A subset of the obese population (25-30%) has been reported to engage in binge eating at least twice weekly (bingers) and to exhibit personality traits and food attitudes similar to those of normoweight bulimic women (bulimics). Tricyclic antidepressants and opiate antagonists effectively suppress binge eating in normoweight bulimics. This 8-wk placebo-controlled, double-blind trial investigated the effect of naltrexone and imipramine on 33 obese bingers and 22 bulimics. Naltrexone (100-150 mg/d) produced a significant reduction in binge duration in bulimics (36 +/- 16%, median +/- SIQR; P = 0.02) whereas imipramine significantly reduced binge duration in obese bingers (88 +/- 31%; P = 0.02). A strong placebo effect was observed in obese bingers and, although a reduction in binge frequency occurred with both naltrexone and imipramine, it was not significantly different from the effect in placebo control subjects. We conclude that naltrexone and imipramine may be useful agents in the treatment of binge eating. 