Selective deficit in executive functioning among patients with borderline personality disorder.

BACKGROUND The aim of this study was to investigate the functioning of patients with borderline personality disorder (BPD) compared to healthy controls on five neuropsychological domains, with regard to the possible effect of differences in IQ.MethodOut-patients and in-patients with BPD (n=35) and healthy comparison subjects (n=35) were tested with an extensive neuropsychological battery, where most cognitive domains were covered by several tests. RESULTS When controlling for the effect of IQ, patients were found to have reduced executive functioning as compared to healthy controls. With regard to the other neuropsychological domains (working memory, attention, long-term verbal memory, and long-term non-verbal memory), no differences were found between the two groups. Within-subject analyses also identified executive functioning as a selective deficit among patients whereas long-term verbal memory was identified as a relative strength. An association was identified between the covariate general intellectual functioning and every neuropsychological domain. No statistically significant differences were found between the subgroups of patients with and without co-morbid post-traumatic stress disorder (PTSD) or between those with and without co-morbid major depression, or between the medicated and unmedicated subgroups on any of the neuropsychological domains. CONCLUSIONS Patients with BPD demonstrate a selective deficit in executive functioning. This corroborates studies that have identified frontal regions as potential neurobiological substrates of the BPD syndrome. The relative strength of the verbal long-term memory function raises pertinent questions regarding the presumed importance of hippocampal structures.