Previous research has documented a range of cognitive deficits in patients with Borderline Personality Disorder (BPD) when compared to normal and depressed control subjects. Deficits have been most notable on visuospatial tests, memory tests and tests of executive functioning. A high incidence of organic insults has also been documented in these patients, including developmental neurological deficits (i.e. attention deficit disorder, learning disability) and acquired neurological dysfunction secondary to trauma, encephalitis or epilepsy.
These findings raise the question as to the extent to which the cognitive deficits reported in this population are associated with the psychopathology and the extent to which they are the result of organic insult. The hypothesis to be tested in this study was that the cognitive deficits associated with BPD are largely the consequence of neurological insult and/or developmental delay.
Using a cross-sectional design, eighty subjects (males and females) who met the criteria for BPD participated in the study. They completed a battery of neuropsychological tests, a comprehensive interview assessing organic status as well as measures of the potentially confounding factors of current levels of depression and anxiety. The tests used had demonstrated sensitivity to the diagnosis of BPD in previous research. It was expected that BPD patients with a probable history of organic insult would perform significantly worse than would BPD patients without such a history. Further, it was anticipated that BPD patients without organic insult would perform at a level that was similar to that of a normal population or a population displaying similar levels of depression or anxiety.
The findings provided partial support for the first hypothesis. Subjects with BPD and a history of organic insult were significantly more impaired on measures of attention than were BPD only subjects and they also displayed significantly weaker performance on several other tests. On the other hand, there were no significant differences between the two groups with respect to tests of either verbal or visual memory.
There was also partial support for the second hypothesis. Subjects with a history of organic insult had mean scores significantly lower than normative samples on 13 of the 17 neuropsychological measures, whereas BPD only subjects were significantly lower than normative samples on only 6 of the 17 measures. The results suggested that the impaired cognitive performance of people diagnosed with BPD can in part be attributed to organic factors but there are also factors associated with the psychopathology itself that contributes to cognitive impairment. The implications of these findings for future research and for clinical practice are discussed.