Placebo and Nocebo Responses, Cortisol, and Circulating Beta-Endorphin

Abstract

A placebo response, ie, a reduced pain level, was seen in the Placebo group at 15 minutes after the injection. The placebo response was not related to stress or to beta-endorphin. Expectation of a pain increase in the Nocebo group led to an increase in cortisol, but the expectation of pain increase and the resultant cortisol increase had no effect on pain.