1. Neuroepidemiology Unit, C Besta National Neurological Institute, Milan, Italy,
2. Department of Organisation and Development, Province of Genoa, Genoa, Italy
3. Department of Neurology, Hospital of Macerata, Macerata, Italy
4. Department of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy
5. Department of Neuroscience, University of Cagliari, Cagliari, Italy
6. Departments of Neurological and Psychiatric Sciences, University of Bari, Bari, Italy
7. Unit of Psychology, Istituto Nazionale per la Cura dei Tumori, Milan, Italy
8. Department of Social and Health Research, Italian Multiple Sclerosis Society, Genoa, Italy