[1] Kings Coll London, Inst Psychiat, Hlth Serv Res Dept, London SE5 8AF, England
[2] S London & Maudsley NHS Trust, London, England
[3] Univ New S Wales, Sch Psychiat, Sydney, NSW, Australia
[4] Kings Coll London, Inst Psychiat, Sch Mental Hlth & Ageing, London, England