1. The Norwegian Centre for Addiction Research, The University of Oslo, Oslo, Norway2Department.of Research and Development in Mental Health Service, Akershus University Hospital, Lorenskog, Norway
2. The Norwegian Centre for Addiction Research, The University of Oslo, Oslo, Norway
3. Department.of Research and Development in Mental Health Service, Akershus University Hospital, Lorenskog, Norway
4. Institute of Clinical Medicine, Campus Ahus, University of Oslo, Oslo, Norway4Health Services Research Unit, Akershus University Hospital, Lorenskog, Norway
5. Department of Addiction Medicine, Haukeland University Hospital, Haukeland, Norway6Faculty of Medicine & Odontology, The University of Bergen, Bergen, Norway
6. The Norwegian Centre for Addiction Research, The University of Oslo, Oslo, Norway7Department of Addiction Medicine, Vestfold Hospital Trust, Tonsberg, Norway
7. Department of Addiction Medicine, Oslo University Hospital, Oslo, Norway