Is the Placebo Effect Real?

December 27, 2010

Harvard researchers think placebo effect may be strongest with full disclosure.

Whether or not the “placebo effect” warrants clinical merit has been a topic of increasing discussion-so much so that Harvard researchers think that effect may be stronger with full disclosure to the patient.

A study published last week in the journal PLoSOne suggests that a placebo’s ability to influence health improvements could rely on full disclosure of a placebo’s character and even intended health benefit.

In order to assess this odd theory, the team of researchers trialed 80 IBS (irritable bowel syndrome) patients (primarily female) on three weeks of no treatment (control) or an open-label placebo. The open-label placebo was described to each patient as “placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes.”

IBS symptoms were evaluated using the IBS Global Improvement Scale (IBS-GIS) and secondary measures, including IBS Symptom Severity Scale (IBS-SSS), IBS Adequate Relief (IBS-AR), and IBS Quality of Life (IBS-QoL). Placebo providers gave equal attention to each patient, regardless of treatment type.

Could the mere suggestion that a placebo was intended to improve IBS symptoms be enough to stimulate an actual, positive human response?

At the midway (day 11) and final (day 21) assessments, the open-label group produced significantly higher mean scores for the primary outcome measure (IBS-GIS) and two of the three secondary measures (IBS-SSS and IBS-AR). The third secondary outcome, IBS-QoL, trended towards a better score for open-label patients at the final assessment.

The results brought researchers to come to a conclusion that “Placebos administered without deception may be an effective treatment for IBS. Further research is warranted in IBS, and perhaps other conditions, to elucidate whether physicians can benefit patients using placebos consistent with informed consent.”

Here’s some further discussion from the study conclusion

"Our results challenge 'the conventional wisdom' that placebo effects require 'intentional ignorance.' Our data suggest that harnessing placebo effects without deception is possible in the context of (1) an accurate description of what is known about placebo effects, (2) encouragement to suspend disbelief, (3) instructions that foster a positive but realistic expectancy, and (4) directions to adhere to the medical ritual of pill taking. It is likely our study also benefited from ongoing media attention giving credence to powerful placebo effects."

Check out the full study for more details on health science and the placebo effect.