The “Placebo effect” is the improvement of a symptom in proportions greater than in an untreated control group, further to treatment with an inactive substance, or after simulation of a therapeutic intervention. In fact, it is crucial for us to understand the Placebo effect as it has an impact on our whole system of care: the ethical dimension of placebo treatments is an important issue; the implications for clinical practice are undeniable, and its role in pharmaceutical and clinical trials raises important concerns, leading us to question the results obtained and our own practices.

By means of a review of the literature, including in particular the work of reference on the subject by Fabrizio Benedetti, 2009Benedetti F. Placebo effects: understanding the mechanisms in health and disease  : Oxford University Press (2009). 293p.

Cliquez ici pour aller à la section Références, the author has looked at all aspects and characteristics of the Placebo effect.

Many studies have shown that the Placebo effect involves neurobiological modifications that can be evidenced using brain scans or pharmacologically, and causes significant clinical effects. The author describes the various theories explaining the Placebo effect, its two main mechanisms being the expectation of the announced result and the conditioning of the cerebral circuit of the reward system, the Nocebo effect, etc. Interpretation of the Placebo effect in clinical trials and the Placebo effect in the treatment of sexual dysfunctions are described in particular detail. The various factors involved in the production of the Placebo effect are also described. This knowledge of the neuropsychological mechanisms of the Placebo effect allows us to better understand the human physiology and has practical consequences on the interpretation of clinical trials and on the physician-patient relationship. The importance of this complex process in clinical drug trials in particular can justify specific large-scale controlled trials, since the stakes are so high in terms of public health. The Placebo effect is universal in nature, since it can appear just as well in Parkinson’s disease as in immunity processes, depression or sexual pathologies.

The author concludes the study with a certain number of recommendations, particularly that the true existence of this phenomenon and its proportions should lead us to be very careful in drawing conclusions from pharmacological trials and more generally speaking, from results of all our treatments. It should also encourage us to adopt a new approach to illnesses where the mode of administration of care and the relationship physician-patient are as important as the actual treatment prescribed.