Impaired working memory and normal sustained attention in borderline personality disorder

Objective: Although reports in the literature describe deficits in working memory in borderline personality disorder (BPD), the evidence is limited and inconsistent. The aim of this study was to evaluate further this cognitive dimension and its clinical correlates in BPD. Method: We compared the performance of 15 BPD patients to 1:1 matched healthy controls on verbal working memory as determined by the sequential letter N-back test and sustained attention as measured using the continuous performance test (CPT). Results: BPD patients performed significantly worse on the N-back test compared to healthy controls (p < 0.05), but not on the CPT. The N-back deficit was more pronounced and significant in the 3-back condition and inversely correlated with impulsivity. Conclusions: These results suggest the presence of working memory deficits in BPD that may be linked to greater impulsivity and sustained by impairment in the dorsolateral prefrontal cortex.