1. Centre of Public Health Sciences, Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
2. Faculty of Psychology, School of Health Sciences, University of Iceland, Reykjavik, Iceland
3. Department of Epidemiology, Harvard School of Public Health, Boston, MA
4. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden
5. National Center for PTSD, VA Boston Healthcare System, Boston, MA
6. Department of Psychiatry, Boston University School of Medicine, Boston, MA
7. Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC
8. Mental Health Services, The National University Hospital of Iceland, Reykjavik, Iceland
9. Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland