Placebo Responses in Trials for Multiple Sclerosis

Dealing with placebo responses in randomized controlled trials for multiple sclerosis presents significant challenges. In studies evaluating both disease-modifying therapies and treatments for symptoms such as spasticity and fatigue, considerable improvements are frequently observed in the placebo arm, with this phenomenon becoming more pronounced in recent studies. Several mechanisms may influence placebo responses, with important implications for trial design and data interpretation. Changes in trial populations due to evolving diagnostic criteria, patient expectations, study design, and the type of treatment or placebo employed, are key factors that should be carefully considered to interpret the results.