Placebos Without Deception: Outcomes, Mechanisms, and Ethics

Int Rev Neurobiol. 2018;138:219-240. doi: 10.1016/bs.irn.2018.01.005. Epub 2018 Apr 4.


Scientific research indicates that open-label and dose-extending placebos (that patients know are placebos) can elicit behavioral, biological, and clinical outcome changes. In this chapter, we present the state-of-the-art evidence and ethical considerations about open-label and dose-extending placebos, discussing the perspective of giving placebos with a rational, as dose extension of active drugs, or expectancy boosters. Previous comprehensive reviews of placebo use have considered how to harness placebo effects in medicine and the need to focus on elements of the clinical encounter as well as patient-clinician relations. Here, we illustrate the similarities and differences between standard (deceptive) placebos, open-label placebos and dose-extending placebos. We conclude that placebos without deception would override ethical barriers to their clinical use. This paves the way to future large-scale, pragmatic randomized trials that investigate the potential of ethical open-label and dose-extending placebos to improve patients' outcomes, and reduce side effects.

Keywords: Conditioning; Dose-extending placebo; Expectancy; Learning; Verbal suggestions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Analgesia* / methods
  • Anticipation, Psychological* / physiology
  • Conditioning, Classical* / physiology
  • Deception*
  • Ethics, Medical*
  • Humans
  • Placebo Effect*