The Reliability of the Placebo Effect in Asthma

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DESCRIPTION (provided by applicant): Placebos are commonly cited as improving signs and symptoms of a wide variety of human diseases both within clinical trials and, by implication, in actual clinical practice. On this basis, the effects of the placebo treatment serve as the baseline against which the effects of the verum treatments are compared. Despite this common practice, it is not known if subjects who manifest a placebo response on a single occasion have the capacity to manifest a response to the repeated administration of a similar placebo (i.e. have a reliable placebo response), and if single or reliable placebo responses in the context of a clinical trial differ from the natural history of the disease under study. In addition, in subjects who do manifest a reliable placebo response, it is not known if this capacity to respond to a placebo is consistent across a variety of placebo modalities (e.g. pharmacological vs. device placebos), or if the capacity to manifest a placebo response is preferentially related to a particular modality. Asthma is a common disease, in which placebo effects have been well described, and in which changes in lung function can occur over short periods of time. In this regard, asthma is an excellent model in which to study many aspects of placebo phenomena. To address our questions regarding the nature of placebo effects in an asthma model, we will study the effects of an inhaled placebo and a validated sham acupuncture needle on lung function in a physiological experiment on volunteers and compare these to lung function changes occurring due to natural history with the following specific aims: Aim 1. To obtain data on the frequency of a reliable response to an inhaled placebo in individuals with stable asthma separate from that occurring due to natural history alone. This information will be used to plan future clinical and mechanistic investigation of the placebo response in conventional and complementary therapies. Aim 2. To obtain data on the frequency of a reliable response to device placebo - sham acupuncture - in individuals with stable asthma separate from that occurring due to natural history alone. This information will be used to plan future clinical and mechanistic investigation of the placebo response in conventional and complementary therapies. Aim 3. To obtain preliminary data on the frequency of a consistent placebo response to an inhaled placebo and a device placebo in individuals with stable asthma. The answers to our research questions will provide important information regarding the properties of placebo responses in distinction from natural history and will form a rational basis for future trials investigating the mechanisms of the placebo phenomenon, for the interpretation of placebo-derived data, and for the design of future R01 applications of placebo-controlled clinical trials of conventional and complementary therapies.