For most of us, the "placebo effect" is synonymous with the power of positive thinking; it works because you believe you're taking a real drug. But a new study rattles this assumption.

Researchers at Harvard Medical School's Osher Research Center and Beth Israel Deaconess Medical Center (BIDMC) have found that placebos work even when administered without the seemingly requisite deception.
The study is published December 22 in PLoS ONE.

Placebos -- or dummy pills -- are typically used in clinical trials as controls for potential new medications. Even though they contain no active ingredients, patients often respond to them. In fact, data on placebos is so compelling that many American physicians (one study estimates 50 percent) secretly give placebos to unsuspecting patients.

Because such "deception" is ethically questionable, HMS associate professor of medicine Ted Kaptchuk teamed up with colleagues at BIDMC to explore whether or not the power of placebos can be harnessed honestly and respectfully.

To do this, 80 patients suffering from irritable bowel syndrome (IBS) were divided into two groups: one group, the controls, received no treatment, while the other group received a regimen of placebos -- honestly described as "like sugar pills" -- which they were instructed to take twice daily.

"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."

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