Do Endorphins Mediate Placebo Analgesia? A Critical Commentary on One of the Seminal Papers.

Abstract

There are only few experimental studies that assess the hypothesis that placebo analgesia is mediated by endogenous opioids. One of these studies [Grevert P, Albert LH, Goldstein A: Partial antagonism of placebo analgesia by naloxone. Pain 1983;16:129-143] had a rather complicated design and data presentation. In this commentary we attempt to clarify the experimental design of that study. Based on a clearer understanding of the study procedures and data analysis we ropose some alternative interpretations of the results.