Encyclopedia of Alternative Medicine | Placebo Effect

Definition

A placebo effect occurs when a treatment or medication with no therapeutic value (a placebo) is administered to a patient and the patient's symptoms improve. The patient believes and expects that the treatment is going to work, therefore it does. The placebo effect is also a factor to some degree in clinically effective therapies, and explains why patients respond better than others to treatment despite similar symptoms and illnesses.

Origins

The word placebo is from the Latin "I shall please." Throughout most of medical history, the placebo effect was the principal treatment physicians offered their patients—e.g. reassurance, attention, and belief in treatment would mobilize patients' internal powers to fight their illnesses. This is still true in indigenous cultures using shamanistic healing which places healing power in objects and rituals. In fact placebos are sometimes called sham...