LAUSR

BACKGROUND Systematic screening is a powerful means by which children and adolescents with posttraumatic stress symptoms (PTSS) can be detected. Reliable and valid measures based on current diagnostic criteria are needed. AIM To investigate the internal consistency and construct validity of the Child and Adolescent Trauma Screen (CATS) in three samples of trauma-exposed children in the US (self-reports: n=249; caregiver reports: n=267; pre-school n=190), in Germany (self-reports: n=117; caregiver reports: n=95) and in Norway (self-reports: n=109; caregiver reports: n=62). METHOD Internal consistency was calculated using Cronbach's α. Convergent-discriminant validity was investigated using bivariate correlation coefficients with measures of depression, anxiety and externalizing symptoms. CFA was used to investigate the DSM-5 factor structure. RESULTS In all three language samples the 20 item symptom score of the self-report and the caregiver report proved good to excellent reliability with α ranging between .88 and .94. The convergent-discriminant validity pattern showed medium to strong correlations with measures of depression (r =.62-.82) and anxiety (r =.40-.77) and low to medium correlations with externalizing symptoms (r =-.15-.43) within informants in all language versions. Using CFA the underlying DSM-5 factor structure with four symptom clusters (re-experiencing, avoidance, negative alterations in mood and cognitions, hyperarousal) was supported (n =475 for self-report; n =424 for caregiver reports). LIMITATIONS The external validation of the CATS with a DSM-5 based semi-structured clinical interview and corresponding determination of cut-points is pending. CONCLUSION The CATS has satisfactory psychometric properties. Clinicians may consider the CATS as a screening tool and for symptom monitoring.