From the Departments of Neurology (J.M.G., M.E., M.A.J.T.), Psychiatry (J.G.M.R.), and Internal Medicine (J.G.M.R.), University Medical Center Groningen, University of Groningen, the Netherlands; Centre for Clinical Brain Sciences (A.C., J.S.), University of Edinburgh, UK; Department of Neurology (J.M.D.), University of Amsterdam, Amsterdam University Medical Center, the Netherlands; and Neurosciences Research Centre (G.N.), Molecular and Clinical Sciences Research Institute, St George's University of London, UK.