Creating placebo responders and nonresponders in the laboratory: boons and banes

摘要

On the basis of the recent insights into the mechanisms of the placebo response, particularly those involved in placebo analgesia, it is possible today to better identify some possible translational implications both within the context of medical practice and within the setting of clinical trials. Whereas in the former case we want to boost placebo responses, in the latter case we need to reduce them. Today we can manipulate these responses in both directions, namely, we can create placebo responders or nonresponders, particularly in pain. However, boons and banes need to be discussed from both a methodological and an ethical perspective. For example, it is important to remember that the improvement that may take place in a patient who has received a placebo may depend on plenty of factors, including spontaneous remission, regression to the mean, methodological biases, such as the experimenter's biased measurements and the patient's biased reports. In addition, the real psychological effect, which is attributable to both expectation and learning mechanisms, may also occur.