Scanning the Global Literature

PLACEBO EFFECTS IN MEDICINE1 For many years, the placebo response has been trivialized and even referred to as an “inert substance.” In a groundbreaking article recently published in The New England Journal of Medicine, Kaptchuk and Miller elucidate mechanisms underlying the placebo response and highlight findings to date regarding placebo effects. They note that placebo effects result from complex neurobiological mechanisms involving neurotransmitters such as endorphins, cannabinoids, and dopamine, not unlike the pathways of common medications. While placebos may provide relief, the authors note that placebos rarely cure. They cite as an example the lack of evidence that placebos can shrink tumors, while noting that placebo interventions may reduce symptoms and side effects of cancer treatments. In highlighting the power of the placebo effect, they also note that symbols such as how the drug is labeled and clinician interactions can dramatically increase the effectiveness of pharmaceuticals. Finally, just as positive expectations can influence positive outcomes, they also describe nocebo effects—psychosocial factors that have the potential to cause adverse consequences. A strong argument is made of the importance of going beyond using placebos as a methodological tool to rigorously studying placebo effects that can help explain how clinicians can be therapeutic agents in the ways they relate to their patients.