It's Not Just the Placebo Effect We Have to Worry About: Introducing Lessebo

Changes on the motor section of the Unified Parkinson's Disease Rating Scale were greater in active-comparator than in placebo-comparator studies, a meta-analysis shows.

When a clinical trial setting involves use of a placebo, patients' expectation of a negative outcome caused by the potential for receiving the placebo is referred to as the “lessebo effect.” To study this effect, researchers conducted a meta-analysis of double-blind, randomized, controlled trials of dopamine agonists for Parkinson disease (PD). They compared changes on the motor section of the Unified Parkinson's Disease Rating Scale (mUPDRS) between trials with active-treatment control arms and those with placebo control arms.

A total of 28 study arms (3277 patients) used an active comparator, and 42 study arms (4554 patients) used placebo controls. The mean mUPDRS score change from baseline to treatment end was 1.6 units greater in the act…

Reviewing Author

Michael S. Okun, MD

Disclosures

Consultant/Advisory BoardParkinson’s Foundation; Tourette Association of America

Speaker’s BureauMedscape/WebMD CME, Movement Disorders Society CME, American Academy of Neurology CME

RoyaltiesBooks4Patients; Demos; Cambridge; Taylor and Francis; Robert Rose; Public Affairs

Grant/Research SupportNational Institutes of Health; Parkinson’s Foundation; Tourette Association of America; University of Florida Foundation

Editorial BoardsTremor and Other Hyperkinetic Movements; JAMA Neurology

Leadership Positions in Professional SocietiesParkinson’s Foundation (Medical Advisor)