1. Department of Drug Statistics, Norwegian Institute of Public Health, 0213 Oslo, Norway
2. Department of Chronic Diseases, Norwegian Institute of Public Health, 0213 Oslo, Norway
3. Norwegian Board of Health Supervision, 0213 Oslo, Norway
4. Department of Research, Innlandet Hospital Trust, 2380 Brumunddal, Norway
5. Child and Adolescent Mental Health Southern Denmark, Mental Health Services in the Region of Southern Denmark, 5000 Odense C, Denmark
6. Department of Mental Health and Suicide, Norwegian Institute of Public Health, 0213 Oslo, Norway