The Yale-Brown Obsessive-Compulsive Scale: a reliability and validity study.

Twenty-eight nondepressed patients with DSM-III obsessive-compulsive disorder completed both the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Leyton Obsessional Inventory (LOI) once a week for a total of three times change. In general, the correlations between the Y-BOCS change scores and the Global Ratings were significantly greater than between the LOI and the Global scores, the Y-BOCS was found to be more reliable than the LOI. Correlations were also obtained for the baseline period between the Y-BOCS and Leyton scores. At the end of a 14-week trial of clomipramine, the Y-BOCS and the LOI were again administered along with a Physician and Patient Global Rating of change. In general, the correlations between the Y-BOCS change scores and the Global Ratings were significantly greater than between the LOI and the Global Ratings. This last finding suggests that the Y-BOCS is a better measure of clinical change than is the LOI.