1. Department of Mental Disorders; Norwegian Institute of Public Health; Oslo Norway
2. Department of Psychology; University of Oslo; Oslo Norway
3. PharmacoEpidemiology and Drug Safety Research Group; School of Pharmacy; University of Oslo; Oslo Norway
4. Norwegian National Advisory Unit on Concurrent Substance Abuse and Mental Health Disorders; Brumunddal Norway
5. Virginia Institute for Psychiatric and Behavioral Genetics; Department of Psychiatry; Virginia Commonwealth University; Richmond VA USA
6. Department of Human and Molecular Genetics and Department of Psychiatry; Virginia Commonwealth University; Richmond VA USA
7. Institute of Clinical Medicine; University of Oslo; Oslo Norway