The placebo effect in asthma

Abstract

The placebo effect is a complex phenomenon occurring across a variety of clinical conditions. While much placebo research has been conducted in diseases defined by self-report such as depression, chronic pain, and irritable bowel syndrome (IBS), asthma has been proposed as a useful model because of its easily measured objective outcomes. Studies examining the placebo response in asthma have not only contributed to an understanding of the mechanisms behind the placebo response but also shed an interesting light on the current treatment and diagnosis of asthma. This paper will review current literature on placebos in general and specifically on the placebo response in asthma. It focuses on what we know about the mechanisms behind the placebo effect, whether there is a specific portion of the population who responds to placebos, which patient outcomes are influenced by the placebo effect, and whether the effect can be augmented.

Conflict of interest statement

Conflict of Interest Stefanie Dutile declares that she has no conflict of interest.

Ted J Kaptchuk declares that he is supported by NCCAM/NIH grant # 2 K24 AT004095.

Michael E. Wechsler declares personal consulting fees from GlaxoSmithKline, Novartis, Cephalon/Teva, Sepracor/Sunovion, NKT Therapeutics, Asthmatx/BSCI, Genzyme, MapPharma, Genentech, Boehringer Ingelheim, Merck, Regeneron, and MedImmune outside the submitted work.

Figures

Fig. 1

Effect of enhanced presentation on placebo and active treatment. Enhanced presentation shows improvement in the subjective outcome of ACQ in the placebo group but not in the treatment group. MNT montelukast, ENH enhanced, PLA placebo, NEUT neutral. A lower ACQ score indicates better asthma control. Courtesy of Robert Wise, M.D.

Fig. 2

Effects of placebo on objective and subjective measures of asthma control. a Percent change in maximum FEV1 with each of the four interventions. FEV1 improvement with albuterol was significantly higher than with each of the other three interventions (p<0.001). b Percent change in subjective improvement with each of the four interventions. Subjective improvement in the albuterol and both placebo arms was greater than that of the no intervention control (p<0.001). From Wechsler et al. [, pp. 123–124]. Copyright © 2011 Massachusetts Medical Society. Reprinted with permission