A Comparison of the Effectiveness of Schema Therapy and Dialectical Behavior Therapy on Integrative Self-Knowledge in Patients with Borderline Personality Disorder

Abstract

This study aimed to compare the effectiveness and durability of schema therapy and dialectical behavior therapy in improving integrative self-knowledge among patients with borderline personality disorder. This semi-experimental study employed a pretest–posttest control-group design with a three-month follow-up. The population consisted of patients diagnosed with borderline personality disorder who attended psychiatric and psychological centers in Tehran during 2024–2025. Forty-five participants were selected through purposive sampling and randomly assigned to three groups (schema therapy, dialectical behavior therapy, and control), each with 15 participants. The two experimental groups received sixteen 60-minute group sessions, while the control group received no intervention. Data were collected using a structured clinical interview for personality disorders, the Borderline Personality Inventory, and the Integrative Self-Knowledge Scale. Repeated-measures analysis of variance and Bonferroni post-hoc tests were applied for data analysis. The results indicated a significant main effect of time and a significant time×group interaction on integrative self-knowledge (p<0.01). Both therapeutic approaches produced significant improvements compared with the control group; however, schema therapy yielded significantly greater gains and larger effect sizes than dialectical behavior therapy. Follow-up findings demonstrated that treatment effects, particularly those of schema therapy, were maintained over time. Schema therapy appears to be more effective and durable than dialectical behavior therapy in enhancing integrative self-knowledge in patients with borderline personality disorder and may be considered a preferable intervention when long-term identity integration is a primary treatment goal.