1 Department of Neurology and Psychiatry, "Sapienza" University of Rome, Italy.
2 Center for Research and Treatment on Cognitive Dysfunctions, Biomedical and Clinical Sciences Department, "Luigi Sacco" Hospital, University of Milan, Italy.
3 National Centre for Epidemiology, Surveillance, and Health Promotion, National Institute of Health, Rome, Italy.
4 Gérontopôle, Centre Hospitalier Universitaire de Toulouse, Toulouse, France; Université de Toulouse III Paul Sabatier, Toulouse, France.