The impact of borderline personality disorder and anxiety on neuropsychological performance in major depression.

Previous studies of neuropsychological performance in borderline personality disorder (BPD) have exhibited mixed results. The high rate of co-occurring major depressive disorder (MDD) in BPD makes it difficult to specify whether neuropsychological deficits in BPD predominantly reflect co-occurring MDD or unique aspects of their psychopathology. To address this issue, 22 participants with borderline personality disorder and concurrent major depressive disorder (BPD-MDD) and 33 participants with MDD and no concurrent personality disorder were compared on a neuropsychological battery that assessed seven domains of performance: general intellectual functioning, motor skill, psychomotor speed, attention, memory, working memory, and executive function. Neuropsychological performance did not differ between BPD-MDD and MDD. However, BPD-MDD participants reported higher levels of anger, anxiety, and of overall emotional distress compared to MDD. When levels of anxiety were controlled, BPD-MDD participants exhibited superior general intellectual performance, psychomotor speed, and attention. Deficits found in previous BPD samples may reflect their susceptibility to co-occurring MDD. The impact of anxiety on neuropsychological performance in BPD, though, indicates a need for future experimental studies of the effects of mood on cognitive function to determine whether mood dysregulation, rather than core depressive symptoms, underlie cognition impairments in BPD.