[1] Univ Liverpool, Dept Primary Care, Liverpool L69 3GB, Merseyside, England
[2] Hosp Univ Marqus de Valdecilla, Unidad Invest Psiquiatria Social, Santander 39008, Spain
[3] Univ Liverpool, Dept Psychiat, Liverpool L69 3BX, Merseyside, England
[4] Univ Wales Coll Med, Div Gen Practice, Wrexham LL13 7YP, Wales
[5] STAKES Mental Hlth Res Grp, Turku 20700, Finland
[6] Univ Oslo, Natl Inst Publ Hlth, Inst Community Med, N-0403 Oslo, Norway
[7] Univ Coll Dublin, Mater Misericordiae Hosp, Dublin 7, Ireland