THE YALE-BROWN OBSESSIVE-COMPULSIVE SCALE - MEASURES OF INTERNAL CONSISTENCY

We examined the construction of the Yale-Brown Obsessive-Compulsive Sc ale (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 examin e the relationship among the 10 items that make up the Y-BOCS instrume nt. Models were computed in which both two- and three-factor solutions were estimated. Within the two-factor solution analyses, the factor d istribution was not so consistent as in the three-factor solution anal yses, and a shift in the factor distribution was noted after treatment . In the three-factor solution analyses, an independent resistance con struct 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.