[1] Karolinska Inst, Dept Med Solna, Stockholm, Sweden
[2] Stockholm Univ, Stress Res Inst, Dept Psychol, Stockholm, Sweden
[3] Macquarie Univ, Sch Psychol Sci, N Ryde, NSW 2109, Australia
[4] Karolinska Univ Hosp, Dept Gastroenterol Dermatovenerol & Rheumatol, Stockholm, Sweden
[5] Danderyd Hosp, Gastroenterol, Stockholm, Sweden
[6] Karolinska Inst, Dept Med Solna, Div Clin Epidemiol, Stockholm, Sweden
[7] Uppsala Univ, Dept Med Sci, Uppsala, Sweden
[8] Karolinska Univ Sjukhuset, SCREESCO, QA33 Karolinska vagen 37A, S-17176 Stockholm, Sweden