Heterogeneity of emotional responses to interpersonal stress in borderline personality disorder

Borderline Personality Disorder (BPD) is characterized by heightened vulnerability to interpersonal stressors, particularly rejection and abandonment. Emotional dysregulation, especially shame and anger, is a hallmark of BPD, yet variability in emotional response profiles and their biological correlates remain insufficiently understood.

We examined emotional and biological responses to an ecological interpersonal stress task replicating real-life abandonment scenarios in 58 female patients with BPD and 57 age-matched healthy controls. Emotional states (shame, anger, sadness, guilt, fear) were assessed at baseline, immediately post-task, and at 5, 15, and 40 min using Likert scales. Blood copeptin levels were measured at the same time points as a biomarker of vasopressinergic stress responses.

Both groups showed significant increases in shame, anger, sadness, and guilt immediately after the task (all p < 0.05). Healthy controls returned to baseline within 40 min, whereas patients with BPD exhibited sustained elevations in shame, anger, and sadness (all p < 0.05). No significant changes in copeptin levels were observed in either group, questioning its utility as a biomarker of acute interpersonal stress. Cluster analysis identified two subgroups within the BPD sample: one characterized by severe dysregulation, high shame-proneness, and an 83 % prevalence of suicide attempts (N = 30), and another with milder reactivity and faster recovery (N = 24).

Findings highlight heterogeneity of emotional responses to abandonment in BPD and underscore the clinical need for subgroup-tailored interventions. Results also challenge the relevance of copeptin as a biomarker of acute interpersonal stress in this population.