[1] Univ Oxford, Cochrane Dementia & Cognit Improvement Grp, Oxford OX1 2JD, England
[2] Univ Oxford, Dept Geratol, Nuffield Dept Clin Neurosci, Oxford OX1 2JD, England
[3] Univ Oxford, Dept Psychiat, Oxford OX1 2JD, England
[4] Univ Amsterdam, Dept Neurol, Acad Med Ctr, NL-1012 WX Amsterdam, Netherlands
[5] Univ Amsterdam, Dept Clin Epidemiol & Biostat, NL-1012 WX Amsterdam, Netherlands
[6] Imperial Coll London, Ctr Mental Hlth, London, England
[7] Univ Western Australia, Western Australian Inst Med Res, Western Australian Ctr Hlth & Ageing WACHA, Perth, WA 6009, Australia
[8] Univ Bristol, Sch Social & Community Med, Ctr Acad Mental Hlth, Bristol BS8 1TH, Avon, England
[9] Univ Cambridge, Inst Publ Hlth, Cambridge CB2 1TN, England
[10] Univ Glasgow, Inst Cardiovasc & Med Sci, Glasgow, Lanark, Scotland
[11] Univ Exeter, Peninsula Technol Assessment Grp PenTAG, Exeter EX4 4QJ, Devon, England
[12] Univ Bern, Inst Social & Prevent Med, CH-3012 Bern, Switzerland
[13] Sunnybrook Hlth Sci Ctr, Sunnybrook Res Inst, Toronto, ON M4N 3M5, Canada
[14] Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, Inst Neurosci & Physiol, Molndal, Sweden
[15] Univ Roma La Sapienza, Dept Neurol & Psychiat, I-00185 Rome, Italy
[16] Univ Calif San Francisco, Inst Hlth & Aging, Dept Social & Behav Sci, San Francisco, CA 94143 USA
[17] Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA
[18] Univ Calif San Francisco, Dept Radiol, San Francisco, CA 94143 USA
[19] Univ Calif San Francisco, Dept Biomed Imaging, San Francisco, CA 94143 USA
[20] Univ Lubeck, Inst Social Med & Epidemiol, Nursing Res Grp, Lubeck, Germany
[21] Univ So Calif, Keck Sch Med, Dept Psychiat Neurol & Gerontol, Los Angeles, CA 90089 USA
[22] Kings Coll London, Inst Psychiat, Dept Neuroimaging, London WC2R 2LS, England