1. Norwegian Institute of Public Health; Oslo Norway
2. Institute and Policlinic of Occupational and Social Medicine; Faculty of Medicine; Technische Universität Dresden; Dresden Germany
3. Department of Psychology; University of Oslo; Oslo Norway
4. Department of Psychotherapy and Psychosomatic Medicine; Faculty of Medicine of the Technische Universität Dresden; Dresden Germany
5. HØKH, Research Centre; Akershus University Hospital; Lørenskog Norway
6. Institute of Clinical Medicine; Campus Ahus, University of Oslo; Lørenskog Norway