Measuring post-traumatic stress disorder and complex post-traumatic stress disorder using the International Trauma Questionnaire: results from a Hungarian clinical and non-clinical sample

Background: The 11th revision of the International Classification of Diseases (ICD-11) simplified the description of post-traumatic stress disorder (PTSD) and also introduced a new trauma-related diagnosis called complex post-traumatic stress disorder (CPTSD). CPTSD is linked to earlier, prolonged interpersonal trauma, and is characterized by a broader range of symptoms, in addition to the core PTSD symptoms. The International Trauma Questionnaire (ITQ) has been developed to assess the new diagnostic criteria. Objectives: The primary aim of our study was to test the factor structure of the ITQ in a clinical and a non-clinical Hungarian sample. We also examined whether the degree of traumatization or the type of trauma experienced was associated with meeting the criteria for PTSD or CPTSD, or with the severity of PTSD or disturbances in self-organization (DSO) symptoms, in both samples. Method: A trauma-exposed heterogeneous clinical sample (N = 176) and a non-clinical sample (N = 229) filled out the ITQ and a modified version of the Life Events Checklist (LEC-5). The factor structure of the ITQ was tested by examining the model fit of seven competing confirmatory factor analysis models. Results: A two-factor second-order model with a second-order PTSD factor (measured by three first-order factors) and a DSO factor (measured directly by six symptoms) had the best fit to the data in both samples if an error correlation was allowed between negative self-concept items. Those in the clinical group who reported more interpersonal and childhood trauma experienced more PTSD and DSO symptoms. Also, there were significant, positive, and weak associations between the total number of different traumas and PTSD and DSO factor scores in both samples. Conclusion: ITQ was found to be a reliable tool to differentiate between PTSD and CPTSD, two related but distinct constructs in a clinical and a non-clinical trauma-exposed sample in Hungary.