The Japanese version of the Posttraumatic Diagnostic Scale: Validity in participants with and without traumatic experiences

•The validity of the Japanese version of the Posttraumatic Diagnostic Scale was examined.•The PDS showed good validity for PTSD diagnosis.•The PDS showed good validity for PTSD severity assessment.

The Posttraumatic Diagnostic Scale (PDS) is a brief, self-report questionnaire developed for the diagnostic screening and assessment of the severity of posttraumatic stress disorder (PTSD); the PDS is based on the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders (4th edition; DSM-IV). We investigated the validity and reliability of the Japanese version of the PDS in a clinical (n = 109) and a non-clinical (n = 116) sample, recruited from an outpatient psychiatric facility and a university student population, respectively. The Japanese versions of the PDS and the Clinician-Administered PTSD Scale (CAPS/DSM-IV) were administered to the participants. The Japanese PDS's diagnostic sensitivity and specificity exceeded 90%. The correlation between the severity scores assessed by the Japanese PDS and the CAPS was also high (r = 0.92). The findings suggest that the Japanese version of the PDS is useful for diagnostically screening PTSD and assessing symptom severity.