The power of placebos is more mysterious than most scientists ever imagined. Sugar pills are perceived as worthless since they have no active ingredients. Researchers use them for comparison when they are testing new drugs. In a double-blind study, neither the investigators nor the subjects know who is getting placebo and who is getting the active drug. If a physician prescribes a sugar pill to a patient without disclosing that it’s a placebo, the practice is considered unethical. Most scientists have assumed that placebos require a level of deception. Telling someone that you are giving him an inactive dummy pill presumably negates the possible psychological benefits.
Such thinking is now being questioned as a result of a new study. Investigators recruited 80 people with irritable bowel syndrome. Half received no treatment at all while the other half got placebo pills to take twice a day. They were told the pills were inactive sugar pills. Despite this information, 59 percent of those on placebo reported an improvement in symptoms after three weeks compared to just 35 percent of the untreated volunteers. The researchers believe that placebos may have a valuable role to play in treating many conditions, but a positive doctor patient relationship seems to be crucial for successful outcomes.
[PLoS One, Dec. 23, 2010]