[1] Radboud Univ Nijmegen Med Ctr, Dept Med Psychol, NL-6500 HB Nijmegen, Netherlands
[2] Radboud Univ Nijmegen Med Ctr, Dept Internal Med, NL-6500 HB Nijmegen, Netherlands
[3] Radboud Univ Nijmegen Med Ctr, Expert Ctr Chron Fatigue, NL-6500 HB Nijmegen, Netherlands