A Placebo Effect in Medication Cost

Michael S. Okun, MD reviewing Espay AJ et al. Neurology 2015 Jan 28.

Placebo medication for Parkinson disease was more effective when it was perceived as expensive.

Can cost affect the response to a Parkinson disease (PD) drug? Investigators conducted a small, prospective, double-blind study to answer this question. Twelve patients with moderate PD who were experiencing motor fluctuations were randomized to two placebo (saline) injections, given in random succession, and told one was a cheap therapy and the other an expensive, subcutaneous, novel, injectable dopamine agonist. At baseline, all subjects had on/off dopaminergic testing and subsequently underwent similar study procedures. The patients were given different descriptions of manufacturing cost prior to the injections. Four hours following the first injection, patients crossed over to the alternate group. Patients completed blinded assessments, including the motor subscale of the Unified Parkinson's Disease Rating Scale, the Purdue Pegboard Test, and a tapping task. The researchers used a visual-motor, associative-learning functional magnetic resonance imaging task to record activation of brain regions.

Both groups improved their motor function, but the benefit was greater when the “expensive” placebo was administered first. Brain activation was greater for the “cheap” drug when given first than for the “expensive” drug when given first. The “cheap” placebo (but not the “expensive” placebo or levodopa) increased activation in the left lateral sensorimotor cortex. The “expensive” placebo improved motor function and decreased brain activation, similar to, but to a lesser extent than, levodopa.

Citation(s):

Espay AJ et al. Placebo effect of medication cost in Parkinson disease: A randomized double-blind study. Neurology 2015 Jan 28; [e-pub].