What aspects of mindfulness and emotion regulation underpin self-harm in individuals with borderline personality disorder?

Background: Self-harm presents significant risk for individuals with borderline personality disorder (BPD). Both self-harm and BPD are associated with deficits in mindfulness and emotion dysregulation. Previous research suggests that thought suppression and emotional inexpressivity may underpin self-harm in people with BPD, suggesting potential links to self-harm functions common for those with BPD. More research is needed to strengthen our understanding of this relationship. Aims: This study examines how BPD symptoms, mindfulness, emotion dysregulation and self-harm functions are related. Methods: Australian community outpatients diagnosed with BPD (N = 110) completed measures of mindfulness, emotion dysregulation and self-harm functions. Serial mediation analyses were conducted to examine relationships between variables. Results: BPD symptoms, chronic emptiness, mindfulness skills, describing and non-reacting, emotion dysregulation areas of emotion regulation strategies and poor emotional clarity were associated with recent self-harm. Various combinations of describing, strategies and clarity mediated the path between emptiness and self-harm functions more likely to be endorsed by individuals with a diagnosis of BPD. Describing was associated with all but anti-suicide function, while strategies was associated with all but anti-dissociation. Conclusion: The study highlights how individuals with BPD experiencing chronic emptiness may benefit from treatment targeting describing skills and adaptive emotion regulation strategies.