In contrast to the DSM-5, which expanded the posttraumatic stress disorder (PTSD) symptom profile to 20 symptoms, a workgroup of the upcoming ICD-11 suggested a reduced symptom profile with six symptoms for PTSD. Therefore, the objective of the study was to investigate the dimensional structure of DSM-5 and ICD-11 PTSD in a clinical sample of trauma-exposed children and adolescents and to compare the diagnostic rates of PTSD between diagnostic systems. The study sample consisted of 475 self-reports and 424 caregiver-reports on the child and adolescent trauma screen (CATS), which were collected at pediatric mental health clinics in the US, Norway and Germany. The factor structure of the PTSD construct as defined in the DSM-5 and in alternative models of both DSM-5 and ICD-11 was investigated using confirmatory factor analyses (CFA). To evaluate differences in PTSD prevalence, McNemar's tests for correlated proportions were used. CFA results demonstrated excellent model fit for the proposed ICD-11 model of PTSD. For the DSM-5 models we found the best fit for the hybrid model. Diagnostic rates were significantly lower according to ICD-11 (self-report: 23.4%; caregiver-report: 16.5%) compared with the DSM-5 (self-report: 37.8%; caregiver-report: 31.8%). Agreement was low between diagnostic systems. Study findings provide support for an alternative latent dimensionality of DSM-5 PTSD in children and adolescents. The conceptualization of ICD-11 PTSD shows an excellent fit. Inconsistent PTSD constructs and significantly diverging diagnostic rates between DSM-5 and the ICD-11 will result in major challenges for researchers and clinicians in the field of psychotraumatology.
Keywords: DSM-5; Factor structure; ICD-11; PTSD; Prevalence.