Social dysfunctioning and brain in borderline personality disorder.

Interpersonal dysfunction is the most prominent and best discriminating characteristic in individuals with borderline personality disorder (BPD). Data from experimental psychopathology point to emotional lability, (auto-)aggression, threat hypersensitivity, poor chance of interpersonal repair, frequent misunderstandings and self/other diffusion as the most significant factors which contribute to the interpersonal derailments typical of BPD. Neuroscientific methods are suitable to elucidate the mechanisms which mediate deficient social functioning in BPD, i.e. affective dysregulation, impulsivity/disinhibition and poor social cognition as well as their neurobiological correlates. Low prefrontoamygdalar coupling together with low activity in inhibiting prefrontal areas, high activity in the mirror neuron system, low activity in the mentalizing circuit, and low anterior insular activity in case of social norm violations are the most significant functional neuroimaging findings that have been reported from individuals with BPD, up to now. In addition, peculiarities of facial emotion processing have been detected by means of psychophysiological methodology in BPD patients. Data have led to preliminary models of social dysfunctioning in BPD that have to be experimentally tested in the future, evolving neuroscience into an important tool to better understand what distresses patients with BPD when communicating with others.