Abstract
Borderline personality disorder (BPD) patients often encounter healthcare system challenges, including stigma and long waitlists, necessitating brief, tailored interventions to reduce suicidal risk and core difficulties. Our study assessed the effectiveness of Mindfulness-Based Cognitive Therapy for Non-Suicidal Self-Injury (MBCT-NSSI) for BPD patients with non-suicidal self-injury (NSSI). Using a non-randomized controlled time-series design, we evaluated participants' self-reported questionnaires at three points. Out of 158 applicants, N = 50 outpatients completed the training. Baseline assessments showed significant emotional dysregulation, elevated depression, hopelessness, impulsivity, dissociative experiences, and frequent self-harming behavior. Dissociation and impulsivity correlated moderately with NSSI, while non-judgement, non-reactivity, and acting with awareness mindfulness facets showed strong associations with clinical scales. Following MBCT-NSSI, significant reductions in NSSI frequency and improvements in mindfulness skills, self-esteem, self-compassion, depression, and impulsivity were observed, though cognitive emotion regulation strategies did not significantly improve. This study reveals some interconnections between NSSI and psychological factors among BPD patients, and the potential benefits of MBCT-NSSI training. While the training is not a replacement for comprehensive therapy, this focused intervention can have a great impact in reducing suicide risk and preventing deterioration.