Cross-cultural validation of the Clinician-Administered PTSD scale for DSM-5, child and adolescent version in Japan

<b>Background:</b> The establishment of a formal diagnosis of post-traumatic stress disorder (PTSD) for children and adolescents is the foundation for advancing pertinent clinical research and formulating proper treatment and management. However, a validated diagnostic tool for PTSD in children and adolescents is lacking in Japan.<b>Objective:</b> To examine the cross-cultural validity and reliability of the Japanese Clinician-Administered PTSD Scale for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), child and adolescent version (CAPS-CA-5-J).<b>Method:</b> Overall, 73 children who had experienced potentially traumatic events were recruited from three medical facilities. The linguistically validated CAPS-CA-5-J was conducted by trained psychiatrists and psychologists. Additionally, children and their caretakers completed questionnaires such as the UCLA PTSD reaction index for DSM-5 (PTSD-RI-5), Depression Self-Rating Scale for Children (DSRDC), and Strength and Difficulties Questionnaire (SDQ); 16 participants were randomly selected for the inter-rater reliability assessment.<b>Results:</b> Owing to missing values in the CAPS-CA-5-J and PTSD-RI-5, 68 children were included in the final analysis. Regarding reliability, the CAPS-CA-5-J showed excellent internal consistency (Cronbach's alpha coefficient = 0.90) and interrater agreement (kappa coefficient = 0.88). Convergent validity was supported by a strong correlation between the total severity scale of the CAPS-CA-5-J and the PTSD-RI-5 scores (Pearson's correlation coefficient = 0.82). Divergent validity was indicated by a moderate correlation between the CAPS-CA-5-J and DSRDC, and no correlation was found with the SDQ scores.<b>Conclusions:</b> This study is the first to validate a structured clinical interview for children and adolescents with PTSD in Japan. The psychometric properties of the CAPS-CA-5-J were good enough and comparable to those reported in previous validation studies. Therefore, the CAPS-CA-5-J can be considered reliable and valid for use in Japan.