THE PLACEBO-EFFECT ON MOOD AND BEHAVIOR - THE ROLE OF THE ENDOGENOUS OPIOID SYSTEM

Evidence from clinical and experimental studies has shown that placebo s influence mood and behavior, that endogenous opioids are involved in the placebo effect, and that the endogenous opioid system is related to psychological events. Recent studies have also demonstrated that th e endogenous opioid system is closely connected with other neurotransm itter systems in the brain. The author suggests that the interaction b etween the endogenous opioid system and different neurotransmitter sys tems in the brain mediates the placebo effect on mood and behavior of both healthy and sick people.