Sarno's Theory could actually be a plausible explanation for the placebo effect. If some percentage of people suffering a condition have psychosomatic symptoms

Sarno's Theory could actually be a plausible explanation for the placebo effect. If some percentage of people suffering a condition have psychosomatic symptoms, when you give them a pill and tell them it will cure them, their brain could switch to creating a different psychosomatic effect (such as headaches instead of backache). This would give the effect of a placebo cure, and side-effects for the placebo cure (which is also something that is observed).