Turkish validity and reliability study of the Yale–Brown Obsessive Compulsive Scale–II (Y-BOCS-II)

The Yale-Brown Obsessive Compulsive Scale – Second Edition (Y-BOCS-II) is an evidence-based, clinician-administered, semi-structured assessment tool developed to evaluate the presence and severity of obsessive-compulsive disorder (OCD) symptoms. Although the scale has undergone validity and reliability studies in various languages, its Turkish version has not yet been psychometrically validated. This study aims to examine the validity, reliability, and factor structure of the Y-BOCS-II within the Turkish population.cThe sample consisted of 269 participants, including 184 individuals diagnosed with OCD and 85 healthy controls. Along with the Structured Clinical Interview for DSM-5 (SCID-5-CV), the following instruments were administered: the Maudsley Obsessive-Compulsive Inventory (MOCI), the Obsessive Beliefs Questionnaire (OBQ-44), the Patient Health Questionnaire (PHQ-9), and the Generalized Anxiety Disorder Scale (GAD-7). The Turkish version of the Y-BOCS-II was evaluated for construct validity, criterion-related validity, internal consistency, test-retest reliability, and inter-rater reliability.cInternal consistency of the Turkish Y-BOCS-II was calculated using Cronbach's alpha. The Cronbach's alpha coefficients were .96 for the total scale, .95 for the obsession subscale, and .93 for the compulsion subscale. Among individuals diagnosed with OCD, these coefficients were .91, .86, and .90, respectively. The inter-rater reliability was found to be excellent, with an intraclass correlation coefficient (ICC) of 0.998. Test-retest reliability was calculated as r = .993, and r = .973 when calculated based on 51 patients diagnosed with OCD. Y-BOCS-II scores showed significant correlations with MOCI, OBQ-44, PHQ-9, and GAD-7. Construct validity was examined via confirmatory factor analysis (CFA), which confirmed the validity of both models proposed in the original article. However, the classical two-factor structure (obsession–compulsion) was found to provide a better fit in the Turkish sample.cIn conclusion, this newly adapted Turkish version of the Yale-Brown Obsessive Compulsive Scale – Second Edition (Y-BOCS-II) is a valid and reliable instrument for assessing the severity of obsessive-compulsive symptoms.