L'effetto placebo

The recent publication of meta-analytic studies that both deny virtually any effectiveness to placebo effect, and attribute to it till 75% of therapeutic efficacy of medical treatments shows the need for a new assessment of this problem. In our study, after a short definition of the effect and a review of the explanations that were given to the effect, we focus our attention on methodological problems, regarding both previous research and meta-analysis, that are published in increasing number in the last few years. Unfortunately, a far exceeding number of clinical research appear subject to many methodological doubts, and meta-analytic studies must discard from 85 to 98% of them; but meta-analysis too appear a mean to obtain any result that one wants to obtain. However, also in reference to alternative medicine, the problem of the placebo deserves a very careful attention, also from the ethical point of view.