Here is a post debunking the “standard placebo narrative”: that there is a magical mind-over-matter process going on that heals of of our ills. In other words, the placebo effect is real.
What is measured in the placebo response includes things like reporting bias, or the desire of subjects to feel better, to please their doctor or the researcher, and to justify their prior decisions (to trust the doctor, take the treatment, enter the study, etc.). Begley fails to distinguish, in other words, between the pain that patients feel and the pain that they report. In studies we never know and cannot measure how much pain patients feel, only how much pain they report. Anything that would affect that reporting will also be lumped into “the placebo response” that is measured in the placebo arm of the study.
This is not quibbling. There is good reason to believe that reporting bias may be the major component of measured placebo effects.
And also very interesting is this study that finds no objective placebo effect. The benefits aren’t real.
In fact Begley did not mention the now famous (or infamous, I guess, depending on your perspective) study by Kaptchuk in which he studied both objective and subjective outcomes in asthma in response to active and placebo interventions. The results – there was a measured placebo response to subjective outcomes, but none for objective outcomes. Asthma is a condition susceptible to things like anxiety and expectation – so it provided a good opportunity to demonstrate objective improvement from placebo interventions, but showed none. This study, while very telling, does not fit the placebo narrative that journalists like to tell, and so is often absent from such articles or misinterpreted when present.