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Placebo and sham treatment are methods used in medical trials to
help researchers determine the effectiveness of a drug or treatment. Placebos
are inactive substances used to compare results with active substances. And in
sham treatments, the doctor goes through the motions without actually
performing the treatment.
A placebo is often used in a drug trial to help show whether the
drug being studied is more effective than an inactive "sugar pill." Some of the
people in the drug trial get the active drug while others get the inactive
placebo. The results of each group are compared.
In a sham treatment, some people get the real treatment while
others get the sham treatment. Then the results are compared.
When a person who is taking the inactive substance or who has
had a sham treatment reports that symptoms have improved, this
improvement is called the placebo effect. It is probably a result of the brain
releasing "feel-good" hormones such as endorphins in response to treatment.
Active drugs and therapies can also have a placebo effect. It can be difficult
for researchers or doctors to know if the reason a drug works is because of its
active ingredient or because of the placebo effect.
Regulations govern studies that use placebos or sham treatments. These studies are always done with the participants' consent.
Current as of:
November 20, 2015
Anne C. Poinier, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Karin M. Lindholm, DO - Neurology
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