1. Department of Alcohol , Tobacco and Drugs, , P.O.Box 222 Skøyen, 0213 Oslo , Norway
2. Norwegian Institute of Public Health , Tobacco and Drugs, , P.O.Box 222 Skøyen, 0213 Oslo , Norway
3. Norwegian National Advisory Unit on Concurrent Substance Abuse and Mental Health Disorders, Kjonerud kompetansesenter, Løvstadveien 7, 2312 Ottestad, Innlandet Hospital Trust , Brumunddal , Norway
4. Institute Clinical of Medicine, UiT The Arctic University of Norway , 9037 Tromsø , Norway
5. Faculty of Social and Health Sciences, Inland Norway University of Applied Sciences , P.O.Box 400 Vestad, 2418 Elverum , Norway
6. Centre for Alcohol and Drug Research, Stavanger University Hospital , P.O. Box 8100, 4068 Stavanger , Norway
7. Faculty of Health Sciences, University of Stavanger , Telegrafdirektør Heftyes vei 73, 4021 Stavanger , Norway
8. Centre for Obesity Research, Clinic of Surgery, St. Olav’s University Hospital , Postboks 3250 Torgarden, 7006 Trondheim , Norway
9. Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology , 7491 Trondheim , Norway
10. Department of Health and Caring Sciences , Faculty of Health and Social Sciences, , Svanehaugvegen 1, 6812 Førde , Norway
11. Western Norway University of Applied Sciences , Faculty of Health and Social Sciences, , Svanehaugvegen 1, 6812 Førde , Norway
12. Førde Hospital Trust , P.O. Box 1000, 6807 Førde , Norway