Depressive Illness and Placebo Response

Abstract

Fifty-three depressed inpatients received placebo treatment as part of a multicenter double-blind placebo-controlled study of an investigational antidepressant, bupropion. Groups of placebo responders and nonresponders were identified based on percentage change on the Hamilton Depression Scale and validated against the Clinical Global Impression Scale. Although the diagnostic and demographic features of responders and nonresponders were generally similar, some differences emerged. Placebo nonresponders were more often associated with male gender, lack of college education, diagnosis of manic-depressive illness and greater lack of insight at baseline. Placebo responders largely consisted of females with a diagnosis of depressive neurosis. When the individual symptoms as measured by the Hamilton Depression Scale were examined, the nonresponders showed improvement only in psychological symptoms (i.e., lack of interest, guilt, and suicide). The responders showed consistent improvement in most symptoms except middle insomnia, loss of weight, and diurnal mood change. These results suggest that depressions of an endogenous nature are unlikely to respond to placebo and when they do respond, the vegetative symptoms are least likely to improve.