Placebos: a review of the placebo response.

Placebos have been a component of healing since the beginning. Whether consciously or unconsciously given, they are largely responsible for the success of medicine before randomized trials. Yet, even in this era of "evidence-based medicine," placebos remain enigmatic, and elicit mixed attitudes from divers disciplines. However, our ignorance is not total. There are a few facts to cling to and old myths to dispel. The effect of placebos seems to encompass such disparate elements as anxiety, conditioning, expectation, the healer's persona, and the attachment of meaning to illness. Placebos may obscure as well as illuminate the truth about treatment effectiveness. Moreover, it is easy to confuse their effect with the natural progression of the disease being treated. Those engaged in treatment trials must recognize and manage the reality of placebos rather than attempt to eliminate or disparage them. Factors that might influence the placebo effect such as age, gender, and social circumstances need prospective study. Meanwhile doctors, through honest and compassionate interactions with patients, should strive to maximize their treatments' benefits. This implies confident reassurance and the provision of some meaning to the person's symptoms.