Meaning, Medicine, and the 'Placebo Effect' by Daniel Moerman

Meaning, Medicine and the 'Placebo Effect' (Cambridge Studies in Medical Anthropology)

Daniel E. Moerman

While not as good overall as Howard Brody's placebo response book that I reviewed here this book is a good complement since it discussed how culture affects the placebo response.

The placebo response is based on the release of various body control chemicals by the brain in response to expectations. The brain is forming expectations and acting on those expectations all the time. In vision it fills in the retinal blind spot where the optic nerve leaves the eyeball. The brain also fills in the gaps between image updates to provide an appearance of continuous motion. If the medio-temporal area of the cortex is damaged the patient sees the world in a strobe light fashion as a series of disconnected images (Quest for Consciousness by Cristof Koch, page 140)

The color and number of pills affects the placebo response (page 47). American medical students were given either one or two pink or blue pills  before a lecture and told one would be a stimulent and another a sedative but not told which was which. In reality the pills were inert. So the study consisted of four groups. The groups who received the two pills had a greater response than those that took one pill (6 out of 119 had severe responses with one pill while 26 out of the 119 had a severe response with two pills). In addition 66% of the students who took the blue tablet reported boredom from the lecture while only 26% of those who took the pink tablet reported boredom. The blue innert tablets enhanced the sedative effect of the lecture while the pink tablets acted to counter-act the lecture's sedative effect.

Shots are more effective than pills. In a study of a blood pressure reducing medication those receiving pills of both the drug and the placebo did not have much of a response but those that instead received shots had a significant response. Those getting the shots of both of the drug and placebo (sterile saline solution) every other week for 12 weeks had significant reductions in blood pressure for 47 (drug) to 59 (placebo) weeks. (page 52). Yet in Europe shots are no better than pills in triggering placebo responses showing how culture can affect expectations (page 79)

Chapter 8 is a very good chapter showing how placebo effects interact with the known neurochemical pain pathways in the brain. This shows better than anything else the connection between mental expectations and neurochemistry.