The placebo effect in Parkinson's disease

Study of the neural mechanisms underlying the placebo effect has increased significantly along with the advances in brain imaging. This is of particular importance in the study of Parkinson's disease, where doctors have attributed the placebo effect in patients for years. Significant effects have been observed in clinical trials for medications as well as more invasive surgical trials including brain stimulation and even stem-cell implantation. In addition to the placebo effect occurring as a byproduct of randomised controlled trials, investigation of the placebo effect itself in the laboratory setting has also shown the presence of a strong placebo effect within this group of patients.

Neuroimaging studies have demonstrated that placebos stimulate the release of dopamine in the striatum of patients with Parkinson's disease and can alter the activity of dopamine neurons using single-cell recording.