Can the Yale-Brown Obsessive Compulsive Scale be used to assess trichotillomania? A preliminary report

Given recent conceptualizations of trichotillomania (TM) as a variant of obsessive compulsive disorder (OCD), clinician-rated measures of obsessive compulsive symptoms have been adapted for use in the assessment of TM. Although the reliability and validity of these instruments have been well-documented in patients with OCD, psychometric properties have not been examined systematically in patients with TM. Here, we evaluate the reliability and validity of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) in a sample of 11 patients with a primary diagnosis of TM. Data addressed the utility of the Y-BOCS for evaluating symptoms of TM, and provided information regarding the proposed overlap between OCD and TM. Initial analyses suggested that interrater reliability, internal consistency, and test-retest reliability for the total score were adequate. However, the range of scores was somewhat restricted, and suggested in particular that interference in daily functioning from TM symptoms is quite low. Both internal consistency and test-retest reliability for the Target Behaviors subscale were inadequate, suggesting that this combined score is inappropriate for use with TM patients. Concurrent validity data using the total score were mixed, although the Y-BOCS did appear to be sensitive to change in TM symptoms over treatment. Implications for the use of the Y-BOCS with TM patients and hypothesized phenomenological differences between TM and OCD are discussed.