The Yale-Brown Obsessive-Compulsive Scale: Measures of internal consistency

We examined the construction of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and performance of subscale items based on data from 204 patients with obsessive-compulsive disorder (OCD) who participated in a multicenter drug treatment study. Factor analysis was used to examine the relationship among the 10 items that make up the Y-BOCS instrument. Models were computed in which both two- and three-factor solutions were estimated. Within the two-factor solution analyses, the factor distribution was not so consistent as in the three-factor solution analyses, and a shift in the factor distribution was noted after treatment. In the three-factor solution analyses, an independent resistence construct emerged in addition to the obsessive and compulsive constructs. Examination of the posttreatment factor scores showed that the Y-BOCS resistance items did not assess OCD symptom change as sensitively as the rest of the Y-BOCS items did.