Placebo: the Belief Effect

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC539455/

 A whole chapter is devoted to the power of belief and its effects on physiology, highlighting the possible differences between individuals, however well matched they are in statistical terms. What the book does not discuss is the conflict between such personal characteristics and evidence-based medicine (EBM), which depends on observations in groups rather than individuals.⁴ Evans' analysis suggests that there are ‘complex ways in which people come to believe their treatment will be effective, sometimes putting the evidence of their senses above the voice of authority, while at other times doing completely the opposite’. Many within the medical profession continue to be guided by similar instincts, describing their thought processes as clinical judgment. It is issues of this sort that have made EBM so hard to implement. As discussed in chapter 5, a dampening effect of placebo on the acute phase response could be interpreted as reflecting the uniquely human social expectation of care from others.⁵ Perhaps the most intriguing part of the book, coming from this former psychotherapist, is the exploration of the role of psychotherapy. His conclusion is that, even if psychotherapy proves to be no more than placebo, this does not necessarily detract from its usefulness; and, if it is better than placebo, our failure to understand how it acts on the brain may be analogous to our ignorance of exactly why certain drugs are effective. Evans is at his best when writing from personal experience. Whatever the reader's conclusions about the scientific arguments, his examples and delivery provide a thoroughly engaging way into this debate.