плацебо

Почему у многих антидепрессантов есть неприятные побочные эффекты? Возможно, потому что антидепрессанты не работают никакие, но те, которые с побочными эффектами успешно обманывают double blind тесты с плацебо: от плацебо не тошнит и поэтому пациент знает, когда принимает настоящее лекарство.

Drug trials are double-blind: neither the patients (paid volunteers) nor the doctors (also paid) are told which group is getting the drug and which is getting the placebo. But antidepressants have side effects, and sugar pills don’t. Commonly, side effects of antidepressants are tolerable things like nausea, restlessness, dry mouth, and so on. (Uncommonly, there is, for example, hepatitis; but patients who develop hepatitis don’t complete the trial.) This means that a patient who experiences minor side effects can conclude that he is taking the drug, and start to feel better, and a patient who doesn’t experience side effects can conclude that she’s taking the placebo, and feel worse. On Kirsch’s calculation, the placebo effect—you believe that you are taking a pill that will make you feel better; therefore, you feel better—wipes out the statistical difference.