Preliminary report: placebo-controlled, double-blind study of the clinical and metabolic effects of desipramine in panic disorder

Abstract

Fifty-six males and females with panic disorder with or without agoraphobia participated in a 12-week, placebo-controlled treatment study of the efficacy of desipramine (DMI). Twenty-six of 28 patients receiving DMI completed the study; 17 of 28 placebo (PBO) recipients completed 12 weeks. Patients receiving DMI responded significantly better than did PBO recipients as measured by Hamilton Anxiety Scale (HAM-A) and global phobia ratings, with a trend toward greater global improvement, but no between-group differences on panic attack frequency were discerned. By Week 12, 22 of 26 (85%) DMI patients were panic-free; 13 of 17 (76%) PBO patients were panic-free. Resting metabolic rate (RMR) was tested on a subset of the patients. Patients receiving DMI showed no effects on RMR or thyroid indices but lost a significant amount of weight; the PBO recipients exhibited no weight loss or RMR effects. In this study, the high PBO response rate obscured treatment group differences on some measures. This study underscores the need for placebo comparisons in treatment studies. In summary, DMI appears to be an effective treatment for panic disorder. DMI appears to have little effect on RMR; a slight but significant weight loss was observed in the DMI but not PBO group.