[1] Univ Hertfordshire, Dept Psychol, Ctr Hlth Serv & Clin Res, Hatfield, Herts, England
[2] Univ West London, Inst Practice Interdisciplinary Res & Enterprise, London, England
[3] Hertfordshire Partnership Univ NHS Fdn Trust, Learning Disabil Serv, St Albans, England
[4] Univ East Anglia, Norwich Med Sch, Norwich, Norfolk, England
[5] Univ East Anglia, Norwich Clin Trials Unit, Norwich, Norfolk, England
[6] Univ Cambridge, Sch Clin Med, Dept Psychiat, Cambridge, England
[7] Hertfordshire Partnership Univ NHS Fdn Trust, Res & Dev, St Albans, England
[8] NIHR Clin Res Network Eastern, Mental Hlth, Div 4, London, England
[9] Univ Hertfordshire, Ctr Res Primary & Community Care, Hatfield, Herts, England
[10] Dartmouth Coll, Dartmouth Inst Hlth Policy & Clin Practice, Hanover, NH 03755 USA