Objective: To examine the effect of cost, a traditionally “inactive” trait of intervention, as contributor to the response to therapeutic interventions.
Methods: We conducted a prospective double-blind study in 12 patients with moderate to severe Parkinson disease and motor fluctuations (mean age 62.4 ± 7.9 years; mean disease duration 11 ± 6 years) who were randomized to a “cheap” or “expensive” subcutaneous “novel injectable dopamine agonist” placebo (normal saline). Patients were crossed over to the alternate arm approximately 4 hours later. Blinded motor assessments in the “practically defined off” state, before and after each intervention, included the Unified Parkinson’s Disease Rating Scale motor subscale, the Purdue Pegboard Test, and a tapping task. Measurements of brain activity were performed using a feedback-based visual-motor associative learning functional MRI task. Order effect was examined using stratified analysis.
Researchers took a bunch of patients and gave them injectable saline (placebo). They told half of them they were getting a “cheap” new drug and the other half an “expensive” new drug. Then they measured them on a number of physical tasks. Four hours later, they reversed the groups.
Everyone got better with the placebo injection. That’s placebo effect number one. But those who got the expensive drug got more of an effect. In fact, quoting the study, “Expensive placebo significantly improved motor function and decreased brain activation in a direction and magnitude comparable to, albeit less than, levodopa”.