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When is a Placebo Acceptable in the Clinic?



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We recently published a paper with the mouthful title “Placebo Use in Pain Management:  A Mechanism-Based Educational Intervention Enhances Placebo Treatment Acceptability”[4].  Before I get to the the findings from that paper, I’d like to provide some context of where this paper fits in the larger placebo analgesia literature.

Placebo is not nothing.  I’m convinced of that.  Many academics are beginning to understand that.  There is plenty of evidence for that conclusion[1,5,7,9,10]. Placebo analgesia is a powerful, physiologically active process.  However, the lay public, and most patients consider placebo to be inert[2].  Related to that belief, most of the public and patients with chronic pain whom we have surveyed consider the use of a placebo deceptive, and view deception as highly undesirable[3].  However, the unacceptability of a placebo is lessened if the placebo is found to be effective[2]!  This suggests that placebos might be more appropriately employed in the clinic if we bring our patients to an understanding similar to our scientific understanding.

So how do we make placebo analgesia more acceptable to patients?  First, placebo is highly used, even in its deceptive formulations [4,6,8].  Furthermore, I strongly suggest to you that placebo or its active ingredients of expectation and conditioning are part of every single treatment that we use with patients.  The evidence overwhelmingly supports that claim.

Forget the term placebo.  How do we use expectation and conditioning to treat people with pain?  How do we do that ethically, without deception, and increase acceptability to patients?

The Kisaalita et al. paper employed an online education about placebo to do just that[4].  In this paper we randomized patients with chronic pain to two conditions.  In one condition they received an online “education” about the empirical evidence for placebo analgesia.  We told this group what we know about brain activation, opioid mechanisms, expectation, and conditioning.  The other group received control education about chronic pain, but no information about placebo.  We assessed placebo acceptability before and after these educational interventions.   As predicted, the patients with the placebo mechanism-based education found placebos to be significantly more acceptable than at pre-intervention, and they found them more acceptable than the control group.  In general, we find that the most acceptable placebo is one that works, is non-deceptive, and has few negative consequences[3].

So what? Should we give everyone a sugar pill and tell them it’s a miracle cure?  Should we sell snake oil?  No, emphatically NO.  We are not suggesting anything of the sort.

These results provide us with an ethical foundation to inform our patients about the full range of active ingredients in our treatments.  We can now truthfully inform them that those treatments we already use (I’m presuming you use empirically validated treatments) work in more than one way.  We can let them know that through positive expectations (yours and theirs), and through classical conditioning, we can even enhance the effectiveness of a treatment.  And we can do it without deception.

What should you do as a treatment provider?  First, pick treatments that have been empirically validated.  Then be enthusiastic about them and the expectation for success.  Engage the patient in the same enthusiasm, and tell them that you are doing that to increase the efficacy of the treatment….because that is also an empirically validated treatment!  Double the value for the money!  We are still working on how to employ classical conditioning into treatment, and have some as yet unpublished data on how to do that.

About Michael Robinson

Dr Robinson is a Professor of Clinical and Health Psychology, Anesthesiology, and Physical Therapy at the University of Florida. He is the Director of the Center for Pain Research and Behavioral Health at the University of Florida.


[1] Craggs J, Price D, Robinson M: Enhancing the placebo response: functional magnetic resonance imaging evidence of memory and semantic processing in placebo analgesia. J Pain , 2014.

[2] Kisaalita N, Robinson M: Analgesic placebo treatment perceptions: acceptability, efficacy, and knowledge. J Pain , 2012.

[3] Kisaalita N, Roditi D, Robinson M: Factors affecting placebo acceptability: deception, outcome, and disease severity. J Pain , 2011.

[4] Kisaalita NR, Hurley RW, Staud R, Robinson ME: Placebo Use in Pain Management: A Mechanism-Based Educational Intervention Enhances Placebo Treatment Acceptability. J Pain 17:257–69, 2016.

[5] Letzen J, Craggs J, Price D, Robinson M: Effective connectivity predicts future placebo analgesic response: A dynamic causal modeling study of pain processing in healthy controls. Neuroimage , 2015.

[6] Price D, Fillingim R, Robinson M: Placebo analgesia: friend or foe? Curr Rheumatol Rep , 2006.

[7] Price DD, Craggs JG, Zhou Q, Verne GN, Perlstein WM, Robinson ME: Widespread hyperalgesia in irritable bowel syndrome is dynamically maintained by tonic visceral impulse input and placebo/nocebo factors: evidence from human psychophysics, animal models, and neuroimaging. Neuroimage 47:995–1001, 2009.

[8] Robinson M, Price D: Placebo analgesia: Widening the scope of measured influences. Pain , 2009.

[9] Sevel LS, Craggs JG, Price DD, Staud R, Robinson ME: Placebo analgesia enhances descending pain-related effective connectivity: a dynamic causal modeling study of endogenous pain modulation. J Pain 16:760–8, 2015.

[10] Vase L, Robinson M, Verne G, Price D: Increased placebo analgesia over time in irritable bowel syndrome (IBS) patients is associated with desire and expectation but not endogenous opioid mechanisms. Pain , 2005.

Commissioning Editor: Associate Professor Claudia Campbell; Associate Editor: Dr Tory Madden

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