Italian International Trauma Questionnaire for Children and Adolescents: Factor structure, measurement invariance, and validity in community and high-risk samples.

Complex posttraumatic stress disorder (CPTSD) is recognized as a distinct diagnosis in the ICD-11. The International Trauma Questionnaire for Children and Adolescents (ITQ-CA) assesses CPTSD symptoms in youth aged 7-17 years; however, no validated Italian version is currently available. This study evaluated the psychometric properties of the Italian ITQ-CA in 488 children and adolescents from community (n = 432) and high-risk residential-care (n = 56) samples. Confirmatory factor analyses compared competing models, and measurement invariance was tested across sex assigned at birth, age, and risk status. The correlated second-order posttraumatic stress disorder (PTSD) and disturbances in self-organization (DSO) model was the best-fitting admissible hierarchical solution, CFI = .990, TLI = .986, RMSEA = .045. Reliability was good, ω = .866-.900; ωH = .800-.823; OHC = .947-.952. Approximate or partial measurement invariance supported latent-mean comparisons: Girls and adolescents had higher PTSD and DSO means than boys and younger participants, ΔM = .554-.879, whereas risk groups did not differ, ΔM = -.055-.006. Concurrent and convergent associations were moderate to large, and regression models identified partially differentiated external correlates, R2 = .563-.618. The findings support the factorial validity and reliability of Italian ITQ-CA symptom scores and their use in Italian youth, and future research should examine functional impairment, longitudinal validity, and clinical replication.