The patients are included using research criteria for severe health anxiety (for ICD-11) and semi-structured interviews developed for DSM-IV, SCAN (general psychopathology) and SCID-II (personality disorders). Criteria for hypochondriasis from ICD-10 and illness anxiety disorder/somatic symptom disorder from DSM-5 are used for subcategorising. Dimensions and traits of personality are assessed by the questionnaire PID-5 included in DSM-5, section III.