Placebos are effective even when patients are aware they are not taking active drugs, finds a new study published in PLoS ONE, the online journal of the Public Library of Science.
Eighty volunteers with irritable bowel syndrome were divided into two groups. One group was prescribed pills but told clearly by researchers that they were "placebo pills made of an inert substance, like sugar pills," while the second group received no pills at all, but the same quality of care from health practitioners.
Those who were on the placebos showed significantly more improvement at both the 11-day midpoint and the conclusion of the study after 21 days, with 60 percent reporting some relief of IBS symptoms, versus only 35 percent of the control group.
Placebos are often used in "blind" studies in order to conceal which patients are receiving the active medication. Frequently, those taking placebos have reported positive results, but it was previously thought that the deception was necessary to make the placebo effective.
While the study’s authors stress that further study is warranted, these findings suggest that physicians may be able to prescribe placebos even while fulfilling their mandate of informed consent.