1. Department of Alcohol, Tobacco and Drugs Norwegian Institute of Public Health Oslo Norway
2. Institute of Clinical Medicine UiT – The Arctic University of Norway Tromsø Norway
3. Norwegian National Advisory Unit on Concurrent Substance Abuse and Mental Health Disorders Brumunddal Norway
4. Department of Chronic diseases and ageing Norwegian Institute of Public Health Oslo Norway
5. Department of Pain Management and Research Oslo University Hospital Oslo Norway
6. Institute of Clinical Medicine, Faculty of Medicine University of Oslo Oslo Norway
7. Department of Mental Disorders Norwegian Institute of Public Health Oslo Norway
8. Norwegian Centre for Addiction Research University of Oslo Oslo Norway