Placebo response: a consideration of its role in therapeutics.

Placebo effects are a potentially inherent element in all treatment responses, and as such, they play a critical role in determining what is "therapeutic." However, the placebo response is also an area of substantial controversy. In the present review, the scientific issues that influence placebo effects are elucidated. The evolution of the concept of placebo and how this has affected its historical importance in therapeutics is considered. The importance of placebo responses in psychiatry and psychotherapy is specifically examined, and recent progress in determining the cognitive and neurobiological bases of placebo effects is reviewed. Finally, it is argued that the placebo response is a cardinal mind-body pathway that promotes salutogenesis and that evidence suggests its relationship to central nervous system activities that are responsible for the concomitant development of positive affects and somatic procedural memories that govern states of mind/body well-being during maternal-infant attachment.