Placebo Effect

The placebo effect is a positive change in a person’s symptoms or condition after the administration of an inert substance (e.g., a sugar pill) or an ineffectual procedure (e.g., a teaching method that is not expected to achieve results) administered under the guise of being an effective treatment. Placebo effects have been demonstrated with a variety of medical conditions, including depression, irritable bowel syndrome, pain, asthma, and Parkinson’s disease, as well as occasionally in educational research. The presence and magnitude of the effect is not constant across situations; rather, it varies as a function of disease condition, type of outcome, and method of administration. Although symptoms under conscious awareness are often susceptible to a placebo effect, objective disease markers, such as blood sugar levels, are ...