Placebo Response in the Pharmacotherapy of Depression

Abstract

The placebo effect is a well-recognized occurrence in the pharmacologic treatment of depression that has generated many research hypotheses. Although placebos are known to exert significant effects across diverse conditions, depression is one psychiatric disorder whose phenomenologic features render it particularly placebo responsive. The placebo response rates reported in clinical trials on antidepressants over the past four or five decades have consistently fallen anywhere from 20%-70%, with a mean of 30%-40%. In this article, the authors first review the literature concerning placebo response in the pharmacotherapy of depression. They discuss how placebo response in depression can be defined and characterized, what may account for the variability in reported placebo response rates, possible predictors of placebo response, and two divergent views on placebo treatment. The article concludes with a discussion of the relevance of these findings for clinical practice and pharmacological research.