“…A body of literature has now been amassed with predictable results: Patients in so-called placebo control groups typically show greater improvement than patients who are assigned to a wait list or no-treatment control group (e.g., Barker, Funk, & Houston, 1988;Bowers & Clum, 1988;Dush, 1986;Prioleau, Murdock, & Brody, 1983;Sheperd, 1984). Indeed, a variety of placebo treatments that emphasize the usual common factors, such as expectations for change, a prescription for activity, discussion, attention, and warmth, yield substantial effect sizes across a variety of disorders, but fail to benefit patients to the degree that active therapies do.…”