Placebo Pills Work, but How Remains a Question
Scientists have no idea why fake drugs called placebos reduced symptoms of irritable bowel syndrome (IBS) in a small study of 80 patients. Past thinking was the effect of a dummy pill came from positive thinking, but new findings show that may not be the case.
Researchers found patients given a pill, who were also told they were getting a dummy drug without medication properties, experienced significant relief from symptoms of IBS.
Even though the study showed placebo was able to treat irritable bowel syndrome, the scientists really don't know how.
In the study, researchers at Harvard Medical School's Osher Research Center and Beth Israel Deaconess Medical Center (BIDMC) studied 80 patients with IBS. One group was given no treatment and the other was clearly informed they would get a pill with not active ingredients and marked as “placebo.
The subjects were told to take the pills, even if they didn’t believe in the “placebo effect” that has been shown to work from past studies comparing patients given real drugs and those given the dummy pills who still get relief of symptoms.
"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 findings showed 59 percent of patients given placebo vs. 35 percent of the control group had symptomatic relief of irritable bowel symptoms that was equivalent to strong drugs used to treat the disorder.
HMS associate professor of medicine Ted Kaptchuk says, 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."
This is not the first study showing placebos work. The novelty of the current findings is that the patients were told exactly what they were getting – something researchers feel may be dishonest in conducting clinical trials. Some physicians give pills to patients that have no active ingredients because the evidence that they work is well documented.
In 2005, the Journal of Neuroscience published the “Neurobiological Mechanisms of the Placebo Effect” - findings that the patient response to taking drugs with no active ingredients might come from a variety of mechanisms. In studies where patients were given the dummy pills but believed they might be getting opiates, scientists saw respiratory depression in study participants that occurs from taking the real thing.
The new study, published December 22, in PLoS ONE, is unique because patients with irritable bowel syndrome knew they were not getting a real drug. The findings open the door for more research that could provide insight into how a placebo can possibly make people feel better, which may have something to do with the mere ritual of taking a pill. For the current study, the researchers warn the findings need to be confirmed in larger trials.
PLoS ONE 5(12): e15591. doi:10.1371/journal.pone.0015591