“Placebos are the ghosts that haunt our house of biomedical objectivity, the creatures that rise up from the dark and expose the paradoxes and fissures in our own self-created definitions of the real and active factors in treatment”.1 So writes Harvard professor Anne Harrington, and today, the mysteries and contradictions generated by the placebo continue to lead modern medicine down perplexing paths. Recently, our limited understanding of the placebo has taken a new turn.
A placebo, which generally takes the form of a sugar pill or sham procedure, often induces a perceived or actual improvement in a medical condition. The history of the term placebo is nearly as mysterious as the effect itself. The word, deriving from the Latin for “I shall please,” made its way into English through an erroneous translation of the Bible2. “Placebo Domino in regione vivorum” (“I will please the lord in the land of the living”) became the opening verse of the Catholic vespers for the dead, sung at funerals by hired mourners in the thirteenth century. Other funeral attendees who sang in hopes of being rewarded by the dead’s relatives garnered the name “placebos.” The word came to mean something like sycophant. It eventually surfaced in medical usage, appearing in Hooper’s 1811 Medical Dictionary as “any medicine adapted more to please than to benefit the patient.”2
We now know that placebos do more than just please – they generate psychobiological effects. While it has long been assumed that placebo effects rely on the ignorance of the patient, a recent study dispels this popular notion. In this study, people suffering from Irritable-Bowel Syndrome either took a placebo pill or received no treatment over three weeks.3 However, in contrast to prior placebo studies, the subjects were explicitly told that they were receiving a placebo, and that placebo treatments often engender significant healing effects. Both groups had equivalent interactions with doctors and clinicians. Remarkably, 59% of patients in the open-label placebo group reported improvement in their symptoms, compared to 35% of the control group. In other words, the placebo effect persisted even when people knew they were taking a placebo.
The recent findings deflate the conventional wisdom that the placebo effect relies on the ignorance of the patient. Traditionally, placebo phenomena have been viewed as a combination of expectation and Pavlovian conditioning. Even with our limited understanding of the connections between mind and body, the traditional perspective now seems inadequate. Many recent findings suggest that placebo effects arise from the overall therapeutic context. Interactions between patient and provider, the intrusiveness of the intervention, and the personality of the patient are examples of psychosocial factors implicated in the placebo effect.4
This perspective is not completely new – medical anthropologists began to argue in the 1980s that nothing short of a broad sociocultural framework could help us make sense of placebo phenomena. Drawing on healing rituals practiced throughout the world, they saw the placebo as a form of ritualized healing.1 Everything from the act of sitting in the doctor’s office to your expectations for improvement are involved in the context of the placebo. Not only do many recent studies back up these claims, but the studies also point to ways that we can harness the placebo effect in clinical settings.
A long-standing hurdle to applying placebos for therapeutic purposes is the policy of informed consent – how can we harness the benefits of the placebo without violating the trust between doctor and patient? Many doctors already push ethical boundaries by prescribing placebo treatments to unwitting patients. In a surprising survey, around 50% of internists and rheumatologists reported prescribing placebo treatments, which included things like antibiotics for viral infections and vitamins for fatigue.5 These doctors intended to appease the patients or alleviate their symptoms, believing that the prescribed treatment would have no adverse or unintended effect. Is this deception? Does this violate the trust between doctor and patient, even though the doctor may have acted in the patient’s best interest?
The recent study demonstrates that we can directly harness placebo effects without violating informed consent.3 More generally, our expanded understanding of the placebo suggests ways to channel placebo effects even when prescribing drugs. This requires recognition of the importance of the overall care environment, instead of viewing the drug as the sole therapeutic agent. Supportive patient-provider relationships go a long way in improving outcomes.6 This is just one of the many elements of the therapeutic context that are involved in placebo phenomena. Consciously attempting to identify and exploit features of the clinical encounter is one means of incorporating placebo effects across diverse clinical settings. The clinical environment can substantially impact patient outcomes, and people show heightened improvement when they have supportive relationships with doctors.4
In harnessing placebo effects, we must also consider how much we value objective versus subjective improvement. A recent study on people with asthma found a striking dissociation between self-reported and physiological improvement.7 Patients were either treated with an albuterol inhaler, a placebo inhaler, fake acupuncture, or nothing at all. The researchers took an objective measure (forced expiratory volume) and a subjective one (self-reported improvement) over the course of the several weeks. As one might have predicted, expiratory capacity only improved in people who used the medicated inhaler. But the placebo groups reported the same level of improvement, even though they experienced no actual physiological benefit. This dissociation between physiology and our feelings is central to placebo phenomena, though we also know that placebos are capable of producing physiological changes.8
So do we want to prescribe placebo-based therapies, even though they might not improve the underlying pathology? Will doctors prescribe open-label placebos in the future? These kinds of questions are likely to be very disease-specific. Placebos do not shrink tumors or lower cholesterol, but can alleviate things like pain and anxiety, which can in turn induce physiological changes. If anything, the mysteries of the placebo show us how little we understand about interactions of the mind and body. But our recognition of the humanistic side suggests ways that we can utilize placebo effects for therapeutic benefit in routine clinical encounters.
- Harrington, Anne. The Placebo Effect: An Interdisciplinary Exploration. Cambridge, MA: Harvard University Press, 1997.
- Aronson, Jeff. “When I Use a Word: Please Please Me.” BMJ 318 (1999): 716.
- Kaptchuk, Ted J., Elizabeth Friedlander, John M. Kelly, M. Norma Sanchez, Efi Kokkotou, Joyce P. Singer, Magda Kowalczykowski, Franklin G. Miller, Irving Kirsch, and Anthony J. Lembo. “Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome.” PLoS ONE 5 no. 12 (2010).
- Finniss, Damien G., Ted J. Kaptchuk, Franklin Miller, and Fabrizio Benedetti. “Biological, Clinical, and Ethical Advances of Placebo Effects.” The Lancet 375 (2010): 686-95.
- Tilburt, Jon C., Ezekial J. Emanuel, Ted J. Kaptchuk, Farr A. Curlin, and Franklin G. Miller. “Prescribing “placebo Treatments”: Results of National Survey of US Internists and Rheumatologists.” BMJ 337 (2008): A1938.
- Kaptchuk, Ted J., J. M. Kelley, L. A. Conboy, R. B. Davis, C. E. Kerr, E. E. Jacobson, I. Kirsch, R. N. Schyner, B. H. Nam, L. T. Nguyen, M. Park, A. L. Rivers, C. McManus, E. Kokkotou, D. A. Drossman, P. Goldman, and A. J. Lembo. “Components of Placebo Effect: Randomised Controlled Trial in Patients with Irritable Bowel Syndrome.” BMJ 336.7651 (2008): 999-1003.
- Wechsler, Michael E., John M. Kelley, Ingrid O. E. Boyd, Stefani Dutile, Gautham Marigowda, Irving Kirsch, Elliot Israel, and Ted J. Kaptchuk. “Active Albuterol or Placebo, Sham Acupuncture, or No Intervention in Asthma.” New England Journal of Medicine 365 no. 2 (2011): 119-126.
- Zubieta, Jon-Kar, Joshua A. Bueller, Lisa R. Jackson, David J. Scott, Yanjun Xu, Robert A. Koeppe, Thomas E. Nichols, and Christian S. Stohler. “Placebo Effects Mediated by Endogenous Opioid Activity on m-Opioid Receptors.” Journal of Neuroscience 25 no. 34 (2005): 7754-762.
- Image credit (Creative Commons): “Pill Tablet.” Flickr. August 26, 2008. Accessed May 8, 2012.
- Image credit (Creative Commons): “Open Healthcare.” Flickr. December 22, 2011. Accessed May 19, 2012.