Association between pathogenic beliefs and personality disorders.

Background and objectives: Personality disorders are significant entities in the field of psychiatry and serve as predisposing factors for Axis I clinical disorder. The Treatment of choice is psychotherapy, and one specific approach is Control Mastery Therapy, which emphasizes addressing Pathogenic beliefs (PB). This study aimed to investigate whether there is a relationship between PB and specific personality disorders and whether these beliefs align with the core features specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM) for that personality disorder. Materials and methods: This study employed a retrospective cross-sectional design and included 319 participants, comprising individuals receiving treatment at the Psychotherapy Clinic at Maharaj Nakorn Chiang Mai Hospital, Faculty of Medicine, Chiang Mai University between 2007 and 2023. All participants were assessed and completed the Structured Clinical Interview for DSM-IV Axis II - Personality Disorders Questionnaire (SCID-II-PQ), Pathogenic Beliefs Scale, and Outcome-Inventory (depression). A generalized linear model (binary logistic regression) was employed, and the predictors included personality disorders. The outcome was the pathogenic belief, and covariates encompassed age, sex, education, clinical diagnosis, and depression score. A sensitivity analysis was conducted to examine the effect on the model when outliers of depressive scores were present. Results: After adjusting for depression, ten personality disorders were found to predict 16 pathogenic beliefs out of the 27 outcomes examined. Notably, histrionic and obsessive-compulsive personality disorders showed no association with specific pathogenic beliefs. Furthermore, certain pathogenic beliefs were predicted by multiple personality disorders, while conversely, some personality disorders were associated with multiple pathogenic beliefs as well. Sensitivity analysis revealed that outliers influenced the relationships between certain disorders and pathogenic beliefs, particularly those with small effect sizes. Conclusions: The profound impact of pathogenic beliefs intertwined with personality disorders, particularly influenced by childhood trauma and evident in Cluster B and schizotypal disorders, underscores the critical need for targeted psychotherapeutic interventions. Addressing these beliefs directly is key to enhancing treatment efficacy and patient outcomes. Pathogenic belief should be elicited in clinical settings regardless of personality disorder, especially those who experienced depression. Moving forward, rigorous research is imperative to validate and refine therapeutic approaches aimed at reshaping pathogenic beliefs, ensuring they become pivotal in transforming clinical practice and advancing mental health care.