The placebo is powerful: Estimating placebo effects in medicine and psychotherapy from randomized clinical trials

Abstract

The logic of the randomized double-blind placebo control group design is presented, and problems with using the design in psychotherapy are discussed. Placebo effects are estimated by examining clinical trials in medicine and psychotherapy. In medicine, a recent meta-analysis of clinical trials with treatment, placebo, and no treatment arms was conducted (Hróbjartsson & Gøtzsche, 2001), and it was concluded that placebos have small or no effects. A re-analysis of those studies, presented here, shows that when disorders are amenable to placebos and the design is adequate to detect the effects, the placebo effect is robust and approaches the treatment effect. For psychological disorders, particularly depression, it has been shown that pill placebos are nearly as effective as active medications whereas psychotherapies are more effective than psychological placebos. However, it is shown that when properly designed, psychological placebos are as effective as accepted psychotherapies.

The self-regulating brain and neurofeedback: Experimental science and clinical promise

“…Treated Condition: When administered a placebo, patients with disorders highly amenable to psychological factors show greater improvements than patients with disorders less amenable to psychological factors (Wampold, Minami, Tierney, Baskin, & Bhati, 2005).…”

Personality Disorder in Childhood and Adolescence comes of Age: a Review of the Current Evidence and Prospects for Future Research

“…However, a general finding from RCTs for treatment of borderline PD in both adolescent and adult samples (206) and in reviews and metaanalyses of psychotherapy outcome research is that there is often little or no difference in efficacy among various bona fide psychotherapeutic treatments (207)(208)(209)(210); a finding commonly referred to as the Dodo bird verdict (211). Taken together this points toward the importance of common factors, extra-therapeutic factors, and placebo effects (206,(212)(213)(214)(215)(216). It may thus be proposed that some of the most important factors related to effecting change have less to do with the specific techniques promoted by the various schools of psychotherapy and more to do with the core and common elements shared across these various therapies (113,161,170,206,(217)(218)(219).…”

Placebo interventions, placebo effects and clinical practice

“…This meta-analysis has been heavily criticized (e.g. [32][33][34][35][36]) for mixing highly heterogeneous studies with control interventions, which might not always be considered placebo, for including studies in which all study groups including the no-treatment group received basic treatment with potential impact on the outcomes measured, as well as for a variety of other reasons. Furthermore, subsequent analyses have provided evidence that a subset of studies with outcomes regulated by the autonomic nervous system is susceptible to placebo treatments ( [37]; see also [38]).…”