title: Eating disorder severity and functional impairment: moderating effects of illness duration in a clinical sample.
abstract: OBJECTIVE
  The aim was to examine duration of illness and body mass index as possible moderators of the relationship between eating disorder severity and functional impairment, as well as psychological distress as a possible mediator of this relationship.
  
  
  METHODS
  The study included 159 patients diagnosed with bulimia nervosa, binge eating disorder or eating disorder not otherwise specified. Regression analysis was applied to assess the effect of the hypothesized moderators and mediators. Eating disorder severity was measured with the Eating Disorder Examination Questionnaire, functional impairment was measured with the Sheehan Disability Scale, and psychological distress was measured with the Symptom Check List-90-R. Duration of illness and body mass index were assessed clinically.
  
  
  RESULTS
  Duration of illness significantly moderated the relationship between eating disorder severity and functional impairment; the relationship was strongest for patients with a shorter duration of illness. Psychological distress partly mediated the relationship between eating disorder severity and functional impairment. Duration of illness significantly moderated the relationship between psychological distress and functional impairment; the strongest relationship was seen for patients with a shorter duration of illness. Body mass index was not a significant moderator of the relationship between ED severity and functional impairment.
  
  
  CONCLUSIONS
  Overall, this study established a link between ED severity, psychological distress and functional impairment indicating that both eating disorder severity and psychological distress are more strongly related to impaired role functioning for patients with more recent onset of an eating disorder. More research in the complex relationship between ED severity and functional impairment is needed.
authors.affiliation: Stolpegaard Psychotherapy Centre, Mental Health Services, Capital Region of Denmark, Stolpegaardsvej 20, 2820, Gentofte, Denmark. annikahelgadottir@gmail.com.|Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, 1353, Copenhagen K., Denmark. annikahelgadottir@gmail.com.
authors.forename: Annika Helgadóttir
authors.initials: AH
authors.lastname: Davidsen
authors.affiliation: Department of Counseling Psychology, School of Education, UW-Madison, Madison, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Hoyt
authors.affiliation: Department of Psychology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Stig
authors.initials: S
authors.lastname: Poulsen
authors.affiliation: Stolpegaard Psychotherapy Centre, Mental Health Services, Capital Region of Denmark, Stolpegaardsvej 20, 2820, Gentofte, Denmark.
authors.forename: Mette
authors.initials: M
authors.lastname: Waaddegaard
authors.affiliation: Stolpegaard Psychotherapy Centre, Mental Health Services, Capital Region of Denmark, Stolpegaardsvej 20, 2820, Gentofte, Denmark.
authors.forename: Marianne
authors.initials: M
authors.lastname: Lau
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D004185:Disability Evaluation; D001068:Feeding and Eating Disorders / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D013315:Stress, Psychological / Q000175:diagnosis* / Q000523:psychology; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
keywords: Body weight; Duration of illness; Eating disorder severity; Functional impairment; Psychological distress