BACKGROUND: Repeated, self-damaging behaviour occurring in the context of borderline personality disorder (BPD) may reflect impairments in decision-making and planning cognition. However, there has been no systematic neuropsychological examination of these particular cognitive functions in patients diagnosed with BPD. Such investigations may improve our understanding of the possible role of brain dysfunction in BPD and improve the characterization of the psychological difficulties associated with this disorder.
METHOD: Forty-two psychiatric patients with a diagnosis of DSM-III-R BPD (41 of whom gave a history of self-harm), without a history of specified 'psychoses' or current major affective disorder, were clinically assessed before completing computerized tasks of decision-making and planning previously shown to be sensitive to frontal lobe dysfunction, and tests of spatial and pattern visual recognition memory previously shown to be sensitive to frontal lobe damage and temporal lobe damage respectively. The performance of the BPD patient group was compared with that of a non-clinical control group consisting of 42 subjects.
RESULTS: The performance of the BPD patients on the decision-making task was characterized by a pattern of delayed and maladaptive choices when choosing between competing actions, and by impulsive, disinhibited responding when gambling on the outcome of their decisions. BPD patients also showed impairments on the planning task. There was no evidence of impaired visual recognition memory. Additional analyses suggested only limited effects of current medication and history of previous substance use disorder.
CONCLUSIONS: These findings suggest that BPD is associated with complex impairments in dissociable cognitive processes mediated by circuitry encompassing the frontal lobes. These impairments may mediate some of the behavioural changes evident in BPD. Further work is needed to examine the specificity of these findings.