1. Department of Mental Health , Norwegian University of Science and Technology , Trondheim , Norway
2. Department of Circulation and Medical Imaging , Norwegian University of Science and Technology , Trondheim , Norway
3. National Competence Centre for Complex Symptom Disorders, St. Olavs Hospital, Trondheim University Hospital , Trondheim , Norway
4. Department of Public Health and Nursing , Norwegian University of Science and Technology , Trondheim , Norway