The Yale-Brown Obsessive Compulsive Scale: factor analysis, construct validity, and suggestions for refinement.

The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is widely acknowledged as the gold standard measure of obsessive-compulsive disorder (OCD) symptom severity. Despite its popularity, a number of questions remain regarding the Y-BOCS' psychometric properties including: (a) whether obsessional and compulsive symptoms contribute independently to global OCD severity and (b) whether the Y-BOCS subscales are valid with respect to other measures of OCD. We examined these issues in a sample of 100 patients with a diagnosis of OCD. While our confirmatory factor analyses failed to reproduce any previously reported models of the Y-BOCS factor structure, exploratory factor analysis indicated a two-factor solution that assessed symptom severity (i.e., time, distress, and interference from obsessions and compulsions) as separate from resistance and control of obsessions and compulsions. In contrast to the Resistance/Control Subscale, the Severity Subscale demonstrated good psychometric properties and construct validity. Based on our findings we recommend revisions to scoring the Y-BOCS.