title: The importance of longitudinal cohort studies in understanding risk and protective factors for dementia.
authors.affiliation: Deputy Editor, International Psychogeriatrics Department of Psychiatry, Level E4, Box 189 Cambridge Biomedical Campus, Cambridge CB2 0SP, UK Email: john.obrien@medschl.cam.ac.uk.
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000175:diagnosis*; D060825:Cognitive Dysfunction / Q000175:diagnosis*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography