Background. Borderline personality disorder (BPD) is characterized by an emotionally unstable and impulsive cognitive and behavioral style. Inhibitory dysfunction has been hypothesized as playing a crucial role in BPD psychopathology. This study aimed to systematically investigate differential inhibitory functions in patients with BPD as compared to healthy controls, and to investigate their expected impairment in the context of aversive emotions by comparing performances in neuropsychological tasks that present both neutral and emotional material.
Method. Unmedicated female patients with BPD (n=28) were compared with age-matched healthy female controls (n=30) in the following tasks: the emotional Stroop test (inhibition of interference), directed forgetting (intentional, resource-dependent inhibition), and an emotional variant of the negative priming task (automatic, resource-independent inhibition).
Results. In comparison with the controls, the BPD patients showed reduced inhibition of negative material in the directed forgetting task and in the negative priming task. No effect was found in the emotional Stroop test. Significant correlations with current affect as well as trait anxiety and anger (but not impulsiveness) were found in the BPD group specifically for negative stimuli, while no such correlations were found in the control group. In addition to inhibitory deficiencies, BPD patients had difficulties remembering positive words in the directed forgetting task.
Conclusions. Our data suggest that individuals with BPD have difficulties in actively suppressing irrelevant information when it is of an aversive nature. Inhibitory dysfunction appears to be closely related to state and trait variables of unstable affect, but not to self-reported impulsiveness.