The Relationship Between Placebo, Nocebo, and Cardiovascular Disease

Whereas the placebo response is the global response to a placebo, including spontaneous remission, regression to the mean, patients' and experimenters' biases, and psychological factors, the placebo effect includes only psychological factors. It is like the difference between drug response and drug effect; whereas the former is the global response to a drug, the latter represents the specific pharmacodynamic effect. Nocebo responses and nocebo effects go in the opposite direction. Most of our knowledge in the cardiovascular system comes from clinical trials, which assess placebo responses rather than placebo effects; thus, our understanding of the underlying psychobiological mechanisms is limited.