title: PTSD or not PTSD? Comparing the proposed ICD-11 and the DSM-5 PTSD criteria among young survivors of the 2011 Norway attacks and their parents.
abstract: BACKGROUND
  The conceptualization of post-traumatic stress disorder (PTSD) in the upcoming International Classification of Diseases (ICD)-11 differs in many respects from the diagnostic criteria in the Diagnostic and Statistical Manual for Mental Disorders, fifth edition (DSM-5). The consequences of these differences for individuals and for estimation of prevalence rates are largely unknown. This study investigated the concordance of the two diagnostic systems in two separate samples at two separate waves.
  
  
  METHODS
  Young survivors of the 2011 Norway attacks (n = 325) and their parents (n = 451) were interviewed at 4-6 months (wave 1) and 15-18 months (wave 2) after the shooting. PTSD was assessed with the UCLA PTSD Reaction Index for DSM-IV adapted for DSM-5, and a subset was used as diagnostic criteria for ICD-11.
  
  
  RESULTS
  In survivors, PTSD prevalence did not differ significantly at any time point, but in parents, the DSM-5 algorithm produced significantly higher prevalence rates than the ICD-11 criteria. The overlap was fair for survivors, but amongst parents a large proportion of individuals met the criteria for only one of the diagnostic systems. No systematic differences were found between ICD-11 and DSM-5 in predictive validity.
  
  
  CONCLUSIONS
  The proposed ICD-11 criteria and the DSM-5 criteria performed equally well when identifying individuals in distress. Nevertheless, the overlap between those meeting the PTSD diagnosis for both ICD-11 and DSM-5 was disturbingly low, with the ICD-11 criteria identifying fewer people than the DSM-5. This represents a major challenge in identifying individuals suffering from PTSD worldwide, possibly resulting in overtreatment or unmet needs for trauma-specific treatment, depending on the area of the world in which patients are being diagnosed.
authors.affiliation: Norwegian Centre for Violence and Traumatic Stress Studies,Pb. 181 Nydalen,0409 Oslo,Norway.
authors.forename: G S
authors.initials: GS
authors.lastname: Hafstad
authors.affiliation: Norwegian Centre for Violence and Traumatic Stress Studies,Pb. 181 Nydalen,0409 Oslo,Norway.
authors.forename: S
authors.initials: S
authors.lastname: Thoresen
authors.affiliation: Norwegian Centre for Violence and Traumatic Stress Studies,Pb. 181 Nydalen,0409 Oslo,Norway.
authors.forename: T
authors.initials: T
authors.lastname: Wentzel-Larsen
authors.affiliation: Department of Psychology - Psychopathology and Clinical Intervention,University of Zurich,Binzmühlestrasse 14/17,8050 Zürich,Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Maercker
authors.affiliation: Norwegian Centre for Violence and Traumatic Stress Studies,Pb. 181 Nydalen,0409 Oslo,Norway.
authors.forename: G
authors.initials: G
authors.lastname: Dyb
mesh_terms: D000293:Adolescent; D000328:Adult; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D010290:Parents / Q000523:psychology*; D015995:Prevalence; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis* / Q000453:epidemiology; D017741:Survivors / Q000523:psychology*; D023481:Terrorism / Q000523:psychology*
keywords: DSM-5; ICD-11; post-traumatic stress disorder; prevalence