[1] Kings Coll London, Inst Psychiat, Hlth Serv & Populat Res Dept, Sect Mental Hlth & Ageing PO26, London SE5 8AF, England
[2] Kings Coll London, Mental Hlth & Neurosci Clin Trials Unit, London SE5 8AF, England
[3] Kings Coll London, Wolfson Ctr Age Related Dis, London SE5 8AF, England
[4] Univ Manchester, Dept Community Based Med, Manchester, Lancs, England
[5] Univ Birmingham, Dept Psychiat, Birmingham, W Midlands, England
[6] Univ E Anglia, Sch Med, Norwich NR4 7TJ, Norfolk, England
[7] Univ Southampton, Clin Neurosci Div, Southampton, Hants, England
[8] UCL, Dept Mental Hlth Sci, London, England
[9] Univ Cambridge, Dept Psychiat, Cambridge, England
[10] Univ Leicester, Dept Psychiat, Leicester, Leics, England
[11] Hull York Med Sch, Inst Rehabil, Kingston Upon Hull, Yorks, England
[12] Alzheimers Soc, London, England
[13] Newcastle Univ, Inst Ageing & Hlth, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[14] Univ Liverpool, Dept Psychiat, Liverpool L69 3BX, Merseyside, England