The Enrichment Window Approach as a Means of Dealing with Placebo Response in Antidepressant Clinical Trials

In this issue, Merlo-Pich et al. present an enrichment-window approach that identifies sites with aberrant mean placebo responses and excludes data from those sites so as to improve drug-placebo discrimination in antidepressant clinical trials. The method appears to increase the signal in situations in which the test drug is better than placebo. However, confirmation of its impact on the rate of false-positive results is needed before the method can be used prospectively.