Deceptive but not open label placebos attenuate motion-induced nausea

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • K. Barnes - , University of Sydney (Author)
  • A. Yu - , University of Sydney (Author)
  • J. Josupeit - , Heinrich Heine University Düsseldorf (Author)
  • B. Colagiuri - , University of Sydney (Author)

Abstract

Objective: Nausea is a common complaint, known to respond to the placebo effect. Existing research has employed deception when administering placebos for nausea, limiting therapeutic translation on ethical grounds. We therefore examined the potential of non-deceptive open-label placebos (OLPs) to reduce nausea. Methods: Galvanic Vestibular Stimulation (GVS) and Virtual Reality (VR) were employed to model nausea in healthy volunteers across two experiments. In both experiments nausea was elicited with and without sham treatment (peppermint vapor and brain stimulation, respectively). In Exp. 1, participants (n = 61) were randomized to deceptive placebo, semi-open placebo, fully-open placebo, or control. In Exp. 2, participants (n = 93) were randomized to deceptive placebo, semi-open placebo, or control. Results: Exp. 1 found limited evidence for a placebo effect (F(1, 56) = 1.15, p =.29, ηp 2 =0.02), even following deceptive treatment (F(1, 56) = 1.92, p =.17, ηp 2=0.03). In Exp. 2, deceptive placebo reduced nausea relative to control (F(1, 89) = 6.91, p =.010, ηp 2=0.07) and OLP (F(1, 89) = 5.47, p =.022, ηp 2=0.06). Pooled Bayesian analysis across experiments provided strong evidence that deceptive placebos reduce nausea relative to control (BF10 = 30.91) and anecdotal evidence for the benefit of deceptive treatment over non-deceptive (BF10 = 2.46) and no benefit of OLP over control (BF10 = 0.63). Conclusions: No positive evidence for OLP effects in nausea were observed. However, a deceptive effect in VR was observed. These findings raise questions regarding the efficacy of open-label intervention in nausea.

Details

Original languageEnglish
Article number109808
JournalJournal of psychosomatic research
Volume125
Publication statusPublished - 2019
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 85070646561

Keywords

Library keywords