Emotion avoidance and fear bradycardia in patients with borderline personality disorder and healthy controls.

Background And Objectives: Exaggerated emotional reactivity is supposed to be essential in the etiology of borderline personality disorder (BPD). More specifically, models of defensive behavior would predict reduced freezing behavior -indicated by fear bradycardia-in response to threat. This study examined automatic fear bradycardia responses in BPD versus healthy controls and the role of emotion dysregulation, more specifically tendencies to avoid emotions.

Methods: Patients with BPD (n = 23) and healthy controls (n = 18) completed questionnaires and then watched neutral, pleasant and unpleasant pictures while heart rate was assessed.

Results: Emotion avoidance interacted with group: it was associated with distinct autonomic responses in healthy controls but not in BPD patients. Controls with lower emotion avoidance tendencies showed bradycardia in response to unpleasant pictures, while controls with higher emotion avoidance tendencies did not. BPD patients showed no bradycardia, irrespective of their emotion avoidance tendencies.

Limitations: This study is limited by a small sample size. Comorbidity or medication intake were not controlled for.

Conclusions: The results may suggest impaired automatic defense responses in BPD. Further understanding of the regulation of distress and defense responses might improve BPD treatment.