title: Introduction.
authors.affiliation: Department of Psychiatry, University of Cambridge, Level E4 Box 189, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK. john.obrien@medschl.cam.ac.uk
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis*; D034462:Dissent and Disputes; D042241:Early Diagnosis; D006801:Humans; D018579:Patient Selection; D015203:Reproducibility of Results; D063189:Symptom Assessment / Q000379:methods / Q000592:standards / Q000639:trends; D054928:Validation Studies as Topic