[1] Oslo Univ Hosp, Div Psychiat, NO-0407 Oslo, Norway
[2] Univ Oslo, Inst Psychiat, Oslo, Norway
[3] Univ Oslo, Dept Behav Sci Med, Oslo, Norway
[4] Univ Oslo, Inst Psychol, Oslo, Norway
[5] Stavanger Univ Hosp, Reg Ctr Clin Res Psychosis, Psychiat Clin, Stavanger, Norway
[6] Univ Bergen, Inst Psychiat, Bergen, Norway
[7] Yale Univ, Sch Med, Dept Psychiat, New Haven, CT USA
[8] Roskilde Psychiat Univ Hosp Fjorden, Roskilde, Denmark