Symptom structure of ICD-11 Complex Posttraumatic Stress Disorder (CPTSD) in trauma-exposed foster children: examining the International Trauma Questionnaire – Child and Adolescent Version (ITQ-CA)

Background: The 11th edition of the International Classification of Diseases (ICD-11) introduces Posttraumatic Stress Disorder (PTSD) and Complex Posttraumatic Stress Disorder (CPTSD) as two distinct trauma-related disorders. Numerous studies support the proposed symptom structure of ICD-11 CPTSD in adults, but only a few studies have examined CPTSD symptom structure in children, reporting diverging results. To assess ICD-11 CPTSD in children, the International Trauma Questionnaire (ITQ) was recently adapted for children and adolescents (ITQ-CA), with no validated German version available yet. Objective: This study aimed (1) to test the symptom structure of ICD-11 CPTSD in a sample of trauma-exposed foster children using the ITQ-CA, and (2) to examine the concurrent, convergent and discriminant validity of the German ITQ-CA. Method: Altogether, 161 Austrian foster children completed a set of standardized measures, resulting in a final sample of 135 trauma-exposed foster children meeting the inclusion criteria. Psychometric properties of the ITQ-CA were assessed using confirmatory factor analysis (CFA), bivariate correlations and multivariate regression. Results: CFA supported ICD-11 CPTSD symptom structure in children as a two-factor higher-order model with PTSD and Disturbances in Self-Organization (DSO) as correlated factors with very good model fit, while a one-factor higher-order model also fitted the data very well. High factor loadings and excellent levels of internal reliability evidenced the psychometric adequacy of the ITQ-CA. Concurrent and convergent validity were evidenced by high correlations between ITQ-CA scales and criterion variables (PTSD symptoms, depression, anxiety, dissociation, lifetime traumatization). Discriminant validity was partly supported by PTSD and DSO being differently predicted by exogenous criterion variables. Conclusions: CPTSD symptom structure in children is in support of the ICD-11 conceptualization. The reliability and validity of the German ITQ-CA are evidenced for the first time, identifying it as an easy-to-use screening instrument to assess ICD-11 PTSD and CPTSD in children. Further implications and areas for upcoming studies are discussed.