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Placebos Work, Even When We Know They’re Placebos

Placebos Work, Even When We Know Theyre PlacebosTaking a placebo appears to be effective even  when the patient is fully aware it’s not a working drug, according to researchers at Harvard Medical School’s Osher Research Center and Beth Israel Deaconess Medical Center (BIDMC).

Placebos have no active ingredients and are mostly used as controls in clinical trials. It’s a proven fact, however, that patients often respond to them, and up until now, this was considered possible due to the power the ‘positive thinking’ associated with the hope of getting better during treatment.  In fact, placebo success is so compelling that many U.S. doctors (one study estimates 50 percent) offer placebos to unaware patients.

There still stands, however, the debatable problem of deceiving patients.  Since this “trickery” presents an ethical dilemma, HMS associate professor of medicine Ted Kaptchuk along with a team from BIDMC decided to investigate if the power of placebos could still be used in an honest and respectable manner.

For the study, 80 participants with irritable bowel syndrome (IBS) were divided into two groups: a control group which received no treatment, and a group given a twice-a-day placebo, which were truthfully described as being “like sugar pills.”

“Not only did we make it absolutely clear that these pills had no active ingredient and were made from inert substances, but we actually had ‘placebo’ printed on the bottle,” says Kaptchuk. “We told the patients that they didn’t have to even believe in the placebo effect. Just take the pills.”

The participants were monitored for three weeks and, at the end of the trial, 59% of the patients given the placebo reported ample symptom improvement as compared to 35% of the control group. Furthermore, participants who took the placebo had rates of improvement about equal to the effects of the most powerful IBS drugs.

“I didn’t think it would work,” says senior author Anthony Lembo, HMS associate professor of medicine at BIDMC and an expert on IBS.

“I felt awkward asking patients to literally take a placebo. But to my surprise, it seemed to work for many of them.”

The authors note that this is a small and narrow study and simply raises interest in the idea that placebos work even for the fully aware patient—a hypothesis that would need confirmation through larger trials.

“Nevertheless,” says Kaptchuk, “these findings suggest that rather than mere positive thinking, there may be significant benefit to the very performance of medical ritual. I’m excited about studying this further. Placebo may work even if patients knows it is a placebo.”

This study was funded by the National Center for Complementary and Alternative Medicine and Osher Research Center, Harvard Medical School and is published in PLoS ONE.

Source:  Harvard Medical School

Placebos Work, Even When We Know They’re Placebos

Traci Pedersen

Traci Pedersen is a professional writer with over a decade of experience. Her work consists of writing for both print and online publishers in a variety of genres including science chapter books, college and career articles, and elementary school curriculum.

APA Reference
Pedersen, T. (2018). Placebos Work, Even When We Know They’re Placebos. Psych Central. Retrieved on November 29, 2020, from
Scientifically Reviewed
Last updated: 8 Aug 2018 (Originally: 27 Dec 2010)
Last reviewed: By a member of our scientific advisory board on 8 Aug 2018
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