[1] Kings Coll London, Natl Addict Ctr, Inst Psychiat Psychol & Neurosci, 4 Windsor Walk, London SE5 8BB, England
[2] Kings Coll London, Inst Psychiat Psychol & Neurosci, Dept Biostat & Hlth Informat, De Crespigny Pk, London SE5 8AF, England
[3] Univ Bristol, Ctr Acad Primary Care, Bristol Med Sch, 39 Whatley Rd, Bristol BS8 2PS, Avon, England
[4] Univ Edinburgh, Sch Hlth Social Sci, 8-9 Hope Pk Sq, Edinburgh 8HQ 9NW, Midlothian, Scotland
[5] Univ York, Dept Hlth Sci, Seebohm Rowntree Bldg, York YO10 5DD, N Yorkshire, England
[6] RESPECT, Green House,244-254 Cambridge Heath Rd, London E2 9DA, England
[7] Univ Gloucestershire, Psychol Sci, The Pk, Cheltenham GL50 2RH, Glos, England
[8] Rochester Inst Technol, 153 Lomb Mem Dr, Rochester, NY 14623 USA