1. Karolinska Institutet, Department of Medicine Solna , Stockholm , Sweden
2. Stress Research Institute, Department of Psychology, Stockholm University , Stockholm , Sweden
3. School of Psychological Sciences Macquarie University , North Ryde, NSW 2109 , Australia
4. Karolinska University Hospital, Department of Gastroenterology , Dermatovenerology and Rheumatology , Stockholm , Sweden
5. Gastroenterology, Danderyd hospital , Stockholm , Sweden
6. Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet , Stockholm , Sweden
7. Department of Medical Sciences, Uppsala University , Uppsala , Sweden