[1] UCL, Dept Psychiat & Behav Sci, London W1N 8AA, England
[2] Our Ladys Hosp, Ennis, Ireland
[3] Univ Wales, DSDC, Bangor, Gwynedd, Wales
[4] Kings Coll London, Sect Community Psychiat, PRISM, Inst Psychiat, London WC2R 2LS, England
[5] Kings Coll London, Hlth Serv Res Dept, Inst Psychiat, London WC2R 2LS, England