The Symptom Checklist-90: Obsessive-Compulsive Subscale: A reliability and validity study.

Twenty-three nondepressed patients with DSM-III obsessive-compulsive disorder completed the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Symptom Checklist-90 (SCL-90), and the National Institute of Mental Health Global Obsessive-Compulsive Scale (NIMH-GOCS) once a week for a total of three times during a 2-week medication-free period and 10 times during a 10-week double-blind drug treatment period. The pretreatment test-retest reliabilities were determined for the Y-BOCS, NIMH-GOCS, and the SCL-90-Obsessive-Compulsive Subscale (SCL-90-OCS). Comparisons of the three instruments revealed that the Y-BOCS and the NIMH-GOCS were significantly more reliable than the SCL-90-OCS. Posttreatment correlations were obtained between change scores on the Y-BOCS and NIMH-GOCS and the SCL-90-OCS. Correlations were high and statistically significant for both the Y-BOCS and the NIMH-GOCS, but the correlations of the SCL-90-OCS with the Y-BOCS, NIMH-GOCS, Physician's Global Rating, and the Patient's Global Rating were poor. The findings suggest that the SCL-90-OCS may not be a sensitive instrument in assessing change in obsessive-compulsive symptoms.