There has been an ongoing debate about placebos on SBM, both in the articles and in the comments. What does it mean that a treatment has been shown to be “no better than placebo?” If our goal is for patients to feel better and they feel better with placebos, why not prescribe them? Do placebos actually do anything useful? What can science tell us about why a patient might report diminished pain after taking an inert sugar pill? The subject is complex and prone to misconceptions. A recent podcast interview offers a breakthrough in understanding.
On her Brain Science Podcast Dr. Ginger Campbell interviewed Dr. Fabrizio Benedetti, a physician and clinical neurophysiologist who is one of the world’s leading researchers on the neurobiology of placebos. A transcript of the interview [PDF] is available on her website for those who prefer reading to listening. The information Dr. Benedetti presents and the expanded remarks by Dr. Campbell after the interview go a long way towards explaining the placebo phenomenon and its consequences for clinical medicine. Dr. Campbell also includes a handy list of references. I’ll try to provide a summary of the main points, but I recommend reading or listening to the original.
A common misconception is that the response to placebos is a purely subjective psychological response involving only the cortical level of the brain; but evidence is accumulating that real, measurable, objective subcortical neurophysiologic phenomena are involved. One of the first hints was a 1978 study showing that the placebo response to pain could be blocked by naloxone, a narcotic antagonist drug, indicating that the placebo must have actually caused an increase in endogenous opioids. (more…)