[1] Univ Bergen, Fac Med, Dept Global Publ Hlth & Primary Care, N-5020 Bergen, Norway
[2] Haukeland Hosp, Dept Addict Med, Bergen Addict Res, N-5021 Bergen, Norway
[3] Norwegian Inst Publ Hlth, Dept Hlth Promot, N-5808 Bergen, Norway
[4] Norwegian Inst Publ Hlth, Ctr Evaluat Publ Hlth Measures, N-0473 Oslo, Norway
[5] Stavanger Univ Hosp, Alcohol & Drug Res Western Norway, N-4068 Stavanger, Norway
[6] Haukeland Hosp, Div Psychiat, N-5021 Bergen, Norway
[7] Univ Oslo, Inst Basic Med Sci, Fac Med, Dept Nutr, N-0317 Oslo, Norway