What does placebo have to do with pain?

 

You may see the terms “placebo effect” and “placebo response” used interchangeably under the umbrella term of “placebo”, but there are some nuances worth teasing out.

 

Originally, “placebo effect” would have described any improvements in symptoms in a group administered an inert treatment (e.g. pill with no medicine, unplugged machine), which would be accounted for by multiple factors, including regression to the mean, bias, co-interventions, “real placebo” responses, etc.. On the other hand, a “placebo response” is restricted to those benefits resulting from a psychophysiological response to an inert treatment (Benedetti 2014).