Placebos work even if people know about it

BOSTON, Dec. 23 (UPI) -- Even knowing a drug is a placebo --"dummy pill"-- does not keep it from working, U.S. researchers say.

Researchers at Harvard Medical School in Boston say the "placebo effect" long linked to the power of positive thinking or "It works because I am told I am taking a real drug," may not require deception to work.

The study published in PLoS ONE, finds twice as many irritable bowel syndrome patients openly given a placebo reported adequate symptom relief versus controls given no treatment. In fact, the patients taking the placebo doubled their rates of improvement to a degree roughly equivalent to effects of the most powerful medications for their illness.

"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," study researcher Dr. Ted Kaptchuk said in a statement. "We told the patients that they didn't have to even believe in the placebo effect. Just take the pills."

Kaptchuk and colleagues divided 80 irritable bowel syndrome patients into a group of controls receiving no treatment and a group receiving a regimen of placebos for three weeks.