BackgroundAttention to the heterogeneous manifestations of obsessive-compulsive symptoms observed in clinical and nonclinical populations has motivated researchers to use tools to identify homogeneous subgroups of obsessive-compulsive disorder (OCD) patients. The Obsessive-Compulsive Trait Core Dimensions Questionnaire (OC-TCDQ) is used to evaluate two motivational dimensions of OCD (harm avoidance (HA) and incompleteness (INC)), which has been developed in recent years based on the core dimensions model, and to classify homogeneous subgroups. This study aimed to validate the Farsi version of the OC-TCDQ in Iran.MethodsThe psychometric properties of the OC-TCDQ were tested in two clinical samples (209 patients with OCD) and nonclinical samples (209 participants without OCD). Confirmatory factor analysis (CFA) was conducted to test the two-factor structure. The measurement invariance between the clinical and nonclinical groups was evaluated. Reliability was tested using Cronbach’s alpha, split-half, and retesting (two-week intervals). Convergent and divergent validity were analysed with Pearson’s correlation and the incremental validity of this scale in predicting Yale-Brown Obsession Scale (Y-BOCS) and Beck Anxiety Inventory (BAI) scores using hierarchical regression analysis. The discriminant validity of the two clinical and nonclinical groups was investigated with a t-test.ResultsSimilar to the original version, the CFA showed a good fit for the two-factor structure. The invariance of measurement between samples, good internal consistency and retest reliability, and convergent and divergent validity of this scale were confirmed. The results of hierarchical regression analysis indicated the increasing validity of this scale in predicting the Y-BOCS and BAI compared to the OBQ-44 (p < 0.05), and comparing the scores of two groups with and without OCD indicated its discriminant validity (p < 0.01).ConclusionThese findings show that the Farsi-OC-TCDQ is a valid tool for evaluating the motivational dimensions of harm avoidance and incompleteness in Iranian individuals with and without OCD, and it allows us to compare the scores across groups.
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