Dorsolateral prefrontal cortex and hippocampus sustain impulsivity and aggressiveness in borderline personality disorder

Background: Borderline Personality Disorder (BPD) patients are characterized by increased levels of aggressivity and reduction of impulse control, which are behavioural dimensions mainly sustained by hippocampus and dorsolateral prefrontal cortex (DLPFC). In this study we aimed at investigating whether hippocampus and DLPFC anatomy may sustain impulsive and aggressive behaviours in BPD. Methods: Fifteen DSM-IV BPD patients (11 females, 4 males) and fifteen 1:1 matched healthy controls (11 females, 4 males) were studied with a 1.5T magnetic resonance imaging (MRI) and underwent a psychopathological assessment in order to measure the severity of aggressive and impulsive traits. Results: Right hippocampal volumes were significantly reduced in BPD patients compared to healthy subjects (p = 0.027), particularly in those with a history of childhood abuse (p = 0.01). Moreover, in patients but not in controls, right hippocampal volumes significantly inversely correlated with aggressiveness and DLPFC grey matter volumes significantly inversely associated with impulsiveness (p <0.05). Conclusions: Our results provide evidence that hippocampus and DLPFC play a separate and unique role in sustaining the control of impulse and aggressive behaviours in BPD patients.