[1] UCL Royal Free & Univ Coll, Sch Med, Dept Psychiat & Behav Sci, RFUC, London NW3 2PF, England
[2] Kings Coll Hosp London, Dept Psychol Med, London, England
[3] Inst Psychiat, Div Psychiat, London, England
[4] Univ Cambridge, Addenbrookes Hosp, Dept Psychiat, Cambridge CB2 2QQ, England
[5] Univ Manchester, Withington Hosp, Sch Psychiat & Behav Sci, Manchester M20 8LR, Lancs, England