The Placebo Effect

The placebo effect is a beneficial effect resulting from a persons anticipation that a treatment will help. The way in which a health care provider interacts with a patient also may bring about a positive response thats independent of any specific treatment.

In research studies, its common for investigators to randomly assign volunteers to either receive the treatment thats being studied or a placebo (an inactive substance that looks like the actual treatment). This helps them distinguish specific effects of the treatment from placebo effects.

Research supported by the National Center for Complementary and Integrative Health has explored several aspects of the placebo effect. One study identified a genetic marker that may predict whether someone will respond to a placebo, another supported the idea that placebo responses may occur outside of conscious awareness, and a third suggested that placebos may be helpful even if patients know theyre receiving placebos.