Pain in Borderline Personality Disorder.

Pain processing in patients with borderline personality disorder (BPD) is abnormal primarily with respect to pain thresholds which are typically elevated or perception of phasic nociceptive stimuli which is reduced. In spite of this common finding, nonsuicidal self-injury (NSSI), often expressed as cutting, is a hallmark sign of the disease and serves to release aversive inner tension. The question thus arises, how does a painful stimulus release inner tension when these patients feel less pain than healthy people? However, intensity discrimination is normal in these patients. Imaging data have provided evidence that inhibitory top-down modulation is increased in BPD patients, and that processing of the affective-emotional pain component is altered. Recent studies have focused on the role of pain, tissue injury and seeing blood in the context of NSSI. Preliminary findings suggest a significant role of pain irrespective of concomitant tissue injury, and of seeing blood expressed as a stronger immediate stress release. Taken together, BPD patients exhibit altered pain processing that can be assigned to altered processing of nociceptive stimuli in prefrontal and limbic brain areas, which may help to mechanistically explain the clinical behavior.