A comparison of placebo responders and nonresponders in subgroups of depressive disorder.

The objective of this study was to determine if the placebo treatment response varied in subgroups of depressed patients (single episode, recurrent, and double depression). Data from placebo-treated patients from seven placebo-controlled clinical trials were pooled and analyzed retrospectively. The placebo response rate was highest for females with a single episode of depression (66.7%) and lowest for females with recurrent depressive episodes (13.3%). Among patients experiencing their first episode, placebo responders had lower Hamilton Rating Scale for Depression (HAMD) total scores at baseline and lower ratings of pschomotor retardation than nonresponders. For patients having a recurrence of an episode, placebo responders had lower baseline ratings of somatic anxiety. The major finding was that patients suffering from their first depressive episode differed from patients with recurrent depressive episodes in the rate of placebo response, effect of gender, and the clinical symptoms that were associated with a positive placebo response.