Placebo Effects

A placebo is a simulated medical treatment (e.g., sugar pill or saline solution) given to patients in lieu of a pharmacologically active substance or procedure (e.g., penicillin or streptomycin). Despite the placebo's inert quality, patients often experience a positive change in health that cannot be attributed to any medicinal or therapeutic treatment. This phenomenon is referred to as the “placebo effect.” Although placebos have been used for centuries, their physiological implications were not fully understood until the mid-1950s. For that reason, a certain level of ambiguity still surrounds placebo effects, including their possible cause and potential application.

The term placebo is Latin for “I shall please.” The use of placebos dates back to the late 18th century. During this time, placebos were commonplace and often viewed ...