Meaning and an Overview of the Placebo Effect.

The placebo effect can be defined as a bodily change due to the symbolic effects of a treatment or treatment situation. It is further explained by the meaning model: a positive placebo response is most likely to occur when the meaning of the illness is altered for the patient in a positive direction. Moerman's suggestion that "placebo effect" be replaced by "meaning response" is based in part on dissatisfaction with the characterization of placebo, which is avoided when one focuses instead more comprehensively on placebo effect. The placebo effect can then be explained by the mental processes of expectancy or conditioning and their effect on specific neuro-chemical processes that bring about end-organ changes.