Predicting Obsessive-Compulsive Personality Disorder Symptoms Based on Defense Mechanisms and Cognitive Distortions Mediated by Mentalization in University Students

The aim of this study was to predict the symptoms of obsessive-compulsive personality disorder (OCPD) based on defense mechanisms and cognitive distortions, with the mediating role of mentalization, among students of selected universities in Isfahan Province. This research employed a descriptive-correlational design and was conducted cross-sectionally. The statistical population included all students of selected universities in Isfahan Province in the year 2024. From this population, 300 students were selected through convenience sampling. Data were collected using four instruments: the Defense Style Questionnaire (DSQ-40), Abdollahzadeh’s Cognitive Distortions Questionnaire (2009), the Mentalization Questionnaire by Fonagy (2016), and the Millon Clinical Multiaxial Inventory-III (MCMI-III). Structural equation modeling (SEM) and path analysis were used for data analysis. The results indicated that both defense mechanisms and cognitive distortions significantly predicted OCPD symptoms, both directly and indirectly through mentalization. Moreover, SEM analyses revealed that mentalization played a significant mediating role in the relationship between defense mechanisms and cognitive distortions with OCPD symptoms. These findings highlight the importance of addressing cognitive and defensive processes and considering the mediating function of mentalization in the diagnosis and treatment of obsessive-compulsive personality symptoms. This study introduces a new model to enhance the understanding of contributing factors to OCPD and emphasizes the necessity of incorporating cognitive and defensive components into therapeutic planning.