Impaired impulse inhibition of emotional stimuli in patients with borderline personality disorder.

This study was aimed to investigate whether BPD patients showed impaired impulse inhibition of emotional and non-emotional stimuli and to explore relevant neuroelectrophysiological mechanisms. A total of 32 BPD patients and 32 matched healthy controls were recruited. Self-reported scales were used to measure psychiatric symptoms. The event-related potentials (ERPs) were recorded when subjects were performing neutral and emotional Stop Signal Task (SST). Group differences in self-reported scores, behavioral variables and ERPs were compared. The BPD group scored significantly higher on impulsivity, severity of BPD symptoms, levels of depression and anxiety than the control group. In neutral SST, no significant group differences were detected in the amplitude and latency of ERPs components induced. In emotional SST, the P2 amplitude of negative emotion was significantly larger than that of neutral emotion in Go trials. In Stop trials, the P2 amplitude of BPD group was significantly smaller than that of control group, and the N2 amplitude of BPD group was significantly greater than that of control group. BPD patients showed impaired inhibition of emotional stimuli rather than non-emotional stimuli. The deficits of emotional impulse control mainly exhibit at the early attention, stimulus evaluation and conflict detection stages.