Conditioning, the Placebo Effect, and Psoriasis

The lack of scientific attention devoted to the placebo effect as a phenomenon in its own right probably reflects the paucity of theoretical positions within which to organize the existing data and design new research. This research addresses the clinical significance of behavior-immune system interactions.

This study will capitalize on conditioned immunosuppressive responses to reduce the cumulative amount of corticosteroid medication used in the treatment of psoriasis. We will continue to treat patients with steroid, but will shift experimental patients from their current schedule of continuous reinforcement (active drug whenever medication is applied) to a partial schedule of reinforcement (active drug a percentage of the time and placebo alone at other times). To equate amount of medication, we will treat another group of patients with a reduced dose of steroid in a standard treatment regimen (continuous schedule of reinforcement).

We hypothesize that, holding cumulative dose constant, a partial schedule of reinforcement will enable patients to be maintained on lower cumulative amounts of corticosteroid than patients treated under a continuous schedule of active drug. This is the first attempt to adopt conditioning principles and use schedules of reinforcement to design regimens of drug therapy. If proven effective, this new approach to pharmacotherapy and placebo effects is likely to stimulate new interdisciplinary research in neuropharmacology and behavioral pharmacology for the treatment of autoimmune disorders and a variety of other chronic diseases.