[1] Kings Coll London, Dept Psychol, Inst Psychiat, London SE5 8AF, England
[2] Kings Coll London, Div Psychol Med, GKT, Sch Med, London WC2R 2LS, England
[3] Univ E Anglia, Sch Hlth Policy & Practice, Clin Psychol Doctoral Programme, Norwich NR4 7TJ, Norfolk, England
[4] UCL, Dept Psychiat & Behav Sci, Royal Free & Univ Coll Med Sch, London, England