1. Center for Clinical Research and Prevention Bispebjerg and Frederiksberg Hospitals Frederiksberg, Copenhagen Denmark
2. Section of Epidemiology Department of Public Health University of Copenhagen Copenhagen Denmark
3. The Research Unit for General Practice and Section of General Practice Department of Public Health University of Copenhagen Copenhagen Denmark
4. Psychiatric Center Copenhagen Frederiksberg, Copenhagen Denmark
5. The Research Clinic for Functional Disorders and Psychosomatics Aarhus University Hospital Aarhus Denmark
6. Psychiatric Center Copenhagen Rigshospitalet Copenhagen Denmark
7. Institute of Clinical Medicine University of Copenhagen Copenhagen Denmark
8. Section of Social Medicine Department of Public Health University of Copenhagen Copenhagen Denmark