The Children’s Yale-Brown Obsessive Compulsive Scale (CY-BOCS) is the most commonly used instrument to assess the symptoms and severity of pediatric obsessive compulsive disorder (OCD). However, only one prior study has evaluated the psychometric properties of the CY-BOCS for assessing young children, ages 5 to 8 years. The limited available evidence suggests that psychometric properties are less favorable with younger children. Thus, the present study aimed to re-examine the technical qualities of the CY-BOCS in a sample of 5 to 8 year olds with early-onset OCD. The sample consisted of 127 younger children, enrolled in a multi-site randomized controlled trial comparing the efficacy of family-based cognitive behavioral therapy to relaxation therapy. The CY-BOCS Total score demonstrated adequate internal consistency, although at a lower level than is typically reported in studies of older children. Internal consistency of the Obsessions and Compulsions subscales was poor. The Total and subscale scores demonstrated good temporal stability over 5 weeks. Agreement between clinician and parent versions was poor at baseline but improved substantially throughout the course of the trial. Results also indicated that the CY-BOCS had good convergent and discriminant validity. Further, certain CY-BOCS items appear more reliable indicators of OCD severity in younger children than others. Limitations, implications, and future directions are discussed, including the potential for further developmentally sensitive refinement of the CY-BOCS for this age group.
