Placebo- Effekt ohne Täuschung
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015591
Abstract
Background: Placebo treatment can significantly influence subjective symptoms. However, it is widely believed that
response to placebo requires concealment or deception. We tested whether open-label placebo (non-deceptive and nonconcealed
administration) is superior to a no-treatment control with matched patient-provider interactions in the treatment
of irritable bowel syndrome (IBS).
Methods: Two-group, randomized, controlled three week trial (August 2009-April 2010) conducted at a single academic
center, involving 80 primarily female (70%) patients, mean age 47618 with IBS diagnosed by Rome III criteria and with a
score $150 on the IBS Symptom Severity Scale (IBS-SSS). Patients were randomized to either open-label placebo pills
presented 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’’ or no-treatment controls with the
same quality of interaction with providers. The primary outcome was IBS Global Improvement Scale (IBS-GIS). Secondary
measures were IBS Symptom Severity Scale (IBS-SSS), IBS Adequate Relief (IBS-AR) and IBS Quality of Life (IBS-QoL).
Findings: Open-label placebo produced significantly higher mean (6SD) global improvement scores (IBS-GIS) at both 11-
day midpoint (5.261.0 vs. 4.061.1, p,.001) and at 21-day endpoint (5.061.5 vs. 3.961.3, p = .002). Significant results were
also observed at both time points for reduced symptom severity (IBS-SSS, p = .008 and p = .03) and adequate relief (IBS-AR,
p = .02 and p = .03); and a trend favoring open-label placebo was observed for quality of life (IBS-QoL) at the 21-day
endpoint (p = .08).
Conclusion: 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.
Trial Registration: ClinicalTrials.gov NCT01010191
