1. Norwegian National Headache Centre, St. Olav’s University Hospital, Trondheim, and Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
2. Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
3. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
4. Department of Neurology, Oslo University Hospital, Oslo
5. National Centre of Violence and Traumatic Stress and University of Oslo
6. HUNT research centre, Institute of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway