Placebo research: the evidence base for harnessing self-healing capacities.

Placebo effects are often considered irrelevant at best and a nuisance at worst for determining what is valuable in medicine. In this paper, we argue that research that involves placebo provides critical information for how the mind, body, and culture heal. Following a newly proposed definition of placebo as a therapeutic meaning response, empirical evidence is reviewed that emphasizes the importance of these effects for developing a science of healing. It is likely that the effects resulting from the individual meaning of an intervention are an important factor of any therapeutic approach. It would be therapeutically desirable to maximize these factors and have good evidence on which to base healing interventions. We show how this could be achieved.