Validation of the Child and Adolescent Trauma Screen-2 (CATS-2) in a Turkish clinical sample: psychometric properties across ICD-11 and DSM-5 frameworks

Background: Early identification of posttraumatic symptoms in children and adolescents is essential for timely intervention. The Child and Adolescent Trauma Screen-2 (CATS-2) is a brief, freely accessible instrument that simultaneously assesses DSM-5 PTSD, ICD-11 PTSD, and ICD-11 complex PTSD (CPTSD) symptoms across child and caregiver report forms. Cross-cultural validation of the CATS-2 in underrepresented settings remains limited. This study examined the psychometric properties of the Turkish CATS-2 in a clinical sample.Method: Participants were 196 children and adolescents referred to a child and adolescent psychiatry outpatient clinic. ICD-11 PTSD and CPTSD diagnoses were established through clinician-administered assessments. Internal consistency, test-retest reliability, convergent and discriminant validity, child-caregiver agreement, confirmatory factor analysis (CFA), known-groups validity, and diagnostic accuracy were examined.Results: The CATS-2C showed good to excellent internal consistency (α=.81–.94) and test-retest reliability (ICC = .86–.90). CFA supported a two-factor correlated model of ICD-11 PTSD and disturbances in self-organization (DSO), and the DSM-5 four-factor model, for both forms. The CATS-2C showed strong convergent validity (r = .79–.89) and negligible associations with externalizing symptoms (r = .08–.12, ns). Known-groups validity was excellent for the CATS-2C (η² = .48–.58) but limited for the CATS-2P (η² = .076–.119). Diagnostic accuracy was good to excellent for the CATS-2C (AUC = .868–.947) and poor to acceptable for the CATS-2P (AUC = .606–.735), all subscales significant. Optimal CATS-2C cut-offs against clinician ICD-11 diagnoses were ≥7 for ICD-11 PTSD (sensitivity = 84%, specificity = 78%), ≥17 for ICD-11 CPTSD (93%, 85%), and ≥30 for DSM-5 PTSD (85%, 89%). Child-caregiver agreement was poor (ICC = .259–.344).Conclusions: The Turkish CATS-2C demonstrated sound psychometric properties, supporting its use as a reliable screening tool in child and adolescent mental health settings. The CATS-2P showed acceptable structural validity and internal consistency but more limited diagnostic discrimination, underscoring the importance of directly assessing symptoms from the child. These findings contribute preliminary evidence regarding ICD-11 PTSD and CPTSD constructs in an underrepresented, middle-income clinical setting.Trial registration: ClinicalTrials.gov identifier: NCT06975852.