1. From the Neuropsychiatric Epidemiology Unit, Institute of Neuroscience and Physiology (X.G., D.G., I.S.), and Sections for Primary Health Care (C. Bengtsson, C. Björkelund) and Public Health Epidemiology (L.L.), Sahlgrenska School of Public Health and Community Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; and the Department of Neurological and Psychiatric Sciences (L.P., M.S.), University of Florence, Florence, Italy.