Understanding Placebo Mechanisms to Reduce Attrition in Psychiatric Trials

Placebo responses in psychiatric trials are clinically significant and variable.1 When placebo response is large, the assay sensitivity of a clinical trial can be impacted, meaning that it can potentially result in a failure to detect efficacy for an active treatment.2 The constituent effects that combine to produce a placebo response are multiple and include both specific placebo mechanisms (eg, expectation effects) and nonspecific effects (eg, regression to the mean).1,3 An additional factor that might impact estimates of both treatment and placebo response is missing data.