Development and validation of the Japanese version of the obsessive-compulsive inventory

BACKGROUND: The Obsessive-Compulsive Inventory (OCI) was designed to evaluate the severity of obsessive-compulsive symptoms in both clinical and non-clinical samples. The aim of the study was to develop a Japanese version of this scale (OCI-J) and validate it in both non-clinical and clinical Japanese samples. FINDINGS: In Study 1, the OCI-J, the Maudsley Obsessional Compulsive Inventory (MOCI), and measures of anxiety and depression were administered to 150 undergraduate students (non-clinical sample) in order to investigate the internal consistency and convergent validity of the OCI-J. Furthermore, 118 non-clinical participants completed the OCI-J after a 2-week interval to determine the test-retest reliability. In Study 2, OCD participants (n = 35), anxiety control participants with panic disorder (n = 22), and healthy control participants (n = 37) completed the OCI-J in order to test its clinical discrimination ability. Correlational analysis indicated moderate to high correlations between the subscales and total scores of the OCI-J and MOCI. In addition, the OCI-J and its subscales demonstrated satisfactory test-retest reliabilities. Finally, the OCI-J showed good clinical discrimination for patients with OCD from healthy and anxiety controls. CONCLUSIONS: The OCI-J is a valid and reliable instrument for measuring OCD symptoms in both clinical and non-clinical samples of Japanese.