1. Home
  2. Health
  3. Arthritis

What Is The Placebo Effect?

By Carol & Richard Eustice, About.com

Updated June 15, 2006

About.com Health's Disease and Condition content is reviewed by the Medical Review Board

Definition: A placebo, as used in research, is an inactive substance or procedure used as a control in an experiment. The placebo effect is the measurable, observable, or felt improvement in health not attributable to an actual treatment.

When a treatment is based on a known inactive substance like a sugar pill, distilled water, or saline solution rather than having real medical value, a patient may still improve merely because their expectation to do so is so strong. To eliminate the effect of positive thinking on clinical trials, researchers often run double-blind, placebo-controlled studies.

For An In-Depth Explanation Of The Placebo Effect:

  • The Healing Power of Placebos
  • Is Every Placebo The Same?
  • The Mysterious Placebo Effect
  • Fast Facts About The Placebo Effect:

    • The word placebo literally means “I will please” in Latin.

    • The first known double-blind placebo-controlled trial was done in 1907.

    • The FDA doesn't require that a drug study include a placebo control group, however, the placebo-controlled trial has long been the standard.

    • The NIH is funding several studies related to the placebo effect.

    Also Known As: Placebo, Placebo response, Power of suggestion
    Common Misspellings: plasebo, placeboo, placebo affect
    Examples:
    The patient thought she was feeling better, but was it real or the placebo effect?

    Sources: Placebo Effect, Robert Todd Carroll, The Skeptic's Dictionary, Skepdic.com, The Mysterious Placebo Effect, by Carol Hart, American Chemical Society, Modern Drug Discovery, July/August 1999: The Healing Power of Placebos, by Tamar Nordenberg, FDA Consumer magazine January-February 2000
    Explore Arthritis
    About.com Special Features

    Learn how you can reduce your your numbers with these nutrition and exercise tips. More >

    Keep yourself, and your family, happy and healthy this fall with these tips. More >

    We comply with the HONcode standard for trustworthy health information: verify here.
    1. Home
    2. Health
    3. Arthritis
    4. Treatments / Surgery
    5. A - Z: Arthritis Research
    6. Clinical Trials: Arthritis
    7. Placebo Effect - What Is The Placebo Effect?>

    ©2009 About.com, a part of The New York Times Company.

    All rights reserved.