Researchers lift the lid on placebos

Of course even the most disappointing research student understands that the key to successfully conducting placebo-based studies is keeping your subjects in the dark.

However a group of researchers from Harvard Medical School (HMS) and Boston’s Beth Israel Deaconess Medical Center (BIDMC) have published a study showing that patients administered sugar pills clearly marked as placebo actually reported a marked decrease in disease symptoms compared with controls.

The researchers divided 80 patients suffering from irritable bowel syndrome (IBS) into two groups. The first ‘control group’, received no treatment, while the second group were administered a regimen of placebos, introduced to the patients as being “like sugar” pills, which they were instructed to take two times a day.

"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," said team leader HMS associate professor of medicine Ted Kaptchuk.

"We told the patients that they didn't have to even believe in the placebo effect. Just take the pills." Patients were then examined for a three week period after which the researchers had in their possession some very interesting data indeed.

At the end of the trial around double the number of patients given placebo (59 percent) reported “adequate symptom” relief compared with the control group (35 percent).

Furthermore, on other outcome measures, patients given the placebo doubled their rates of improvement to a degree roughly equivalent to the effects of the most powerful IBS medications.

"I didn't think it would work," said senior author Anthony Lembo, HMS associate professor of medicine at BIDMC and a renowned authority 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 study was, however, conducted on a relatively small scale with significantly more inquiry needed before arriving at any solid conclusions.

"Nevertheless," said 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 know it is a placebo."

The study was published in the current issue of PLoS ONE