Cognition in adults with borderline personality disorder.

Objective: Borderline personality disorder (BPD) is a common and disabling mental health disorder and has detrimental effects on affected individuals across multiple domains. We aimed to investigate whether individuals with BPD differ from control subjects in terms of cognitive functions, and to see if there is a relationship between cognitive functions, impulsivity, and BPD symptom severity.
Methods: BPD individuals (n = 26; mean age = 26.7; 69.2% female) and controls (n = 58; mean age = 25.3; 51.7% female) were enrolled. Intra/Extra-Dimensional Set Shift (IED) and One Touch Stockings of Cambridge (OTS) tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to assess cognitive functions. Barratt Impulsivity Scale-version 11 (BIS-11) was administered to measure impulsivity and both the Zanarini Scale for Borderline Personality Disorder self-report and the clinician-administered versions were used to assess BPD symptom severity.
Results: BPD group showed significantly impaired cognitive performance on the IED task versus controls, but there was not a significant difference in the OTS task. BPD symptom severity was positively correlated with trait (BIS-11) impulsivity and no correlation was found between BPD symptom severity and cognitive functions.
Conclusions: This study suggests people with BPD experience impaired cognitive flexibility and heightened impulsivity. Only impulsivity appeared to be directly related to symptom severity, perhaps indicating that cognitive inflexibility could be a vulnerability marker. Future research should focus on a longitudinal approach to extend clinical and theoretical knowledge in this area.