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Benefits of a Placebo in Adults With IBS Do Not Depend on Deception, Study Shows

Doctor speaking to elderly man.

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According to a recent study published in the journal PLoS One, placebos given without deception improved symptoms of irritable bowel syndrome (IBS). A number of studies have shown improvements in symptoms and measurable physiological changes in response to placebo treatments, but it has generally been assumed that the beneficial responses to placebo are based on concealment (i.e., patients do not know if they are receiving a placebo or an active treatment). Despite the recognition of possible benefit, the use of a placebo without the patient's knowledge poses an ethical problem for most clinicians. The new study examined the use of a placebo pill, given without deception, compared with no treatment in relieving symptoms of IBS.

Researchers, funded in part by NCCAM, followed 80 adults with IBS (aged 18 or older) over the course of 3 weeks. Participants were randomly assigned to receive either placebo pills (two pills twice a day) or no treatment. The participants in the placebo group were informed that “placebo pills, made of an inert substance, like sugar pills, have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body healing processes.” The quality of the practitioner-patient interaction was similar in both groups. The researchers assessed the participants at the midpoint and at the end of the study, with a brief physical examination and patient questionnaires that measured symptom improvement. The researchers found that the participants in the placebo group had significantly better scores in global improvement, severity of symptoms, and adequate relief than the no-treatment group at both the midpoint and the end of the study. In addition, the placebo group had a trend toward improvement in quality of life.

Based on these findings, the researchers suggest that placebo treatments when administered without concealment, and with a plausible rationale of placebo's potential effects, may produce beneficial responses in patients. They also suggest that placebo responses without deception are possible if participants receive an accurate explanation of the placebo effect, instructions that give a positive but realistic expectation of results, and directions on taking pills as instructed. In addition, the researchers note that more studies are needed on IBS, as well as other conditions, to confirm that placebos can be beneficial when used openly and to determine the best methods for administering such treatments.


Publication Date: 
December 22, 2010

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This page last modified February 02, 2015