Neuropsychological deficits correlate with symptoms severity and cortical thickness in Borderline Personality Disorder

Background: Neuropsychological abnormalities have been proposed to contribute to the development and maintenance of Borderline Personality Disorder (BPD). Previous meta-analyses and reviews confirmed deficits in a broad range of cognitive domains, including attention, cognitive flexibility, memory, executive functions, planning, information processing, and visuospatial abilities, often suggested to underlie brain abnormalities. However, no study directly explored the structural neural correlates of these deficits in BPD, also accounting for the possible confounding effect of pharmacological treatments, often used as adjunctive symptom-targeted therapy in clinical setting.

Methods: In this study we compared the performance of 24 BPD patients to 24 healthy controls obtained at the neuropsychological battery "Brief Assessment and Cognition in Schizophrenia", exploring the relationship between the cognitive impairments and current symptomatology, brain grey matter volumes and cortical thickness, controlling for medications load.

Results: Data revealed deficits in verbal memory and fluency, working memory, attention and speed of information processing and psychomotor speed and coordination when medication load was not in the model. Correcting for this variable, only the impairment in psychomotor abilities remained significant. A multiple regression confirmed the effect of this neuropsychological domain on the severity of BPD symptomatology (Borderline Evaluation of Severity Over Time). In BPD, the performance at psychomotor speed and coordination was also directly associated to cortical thickness in postcentral gyrus.

Limitations: Relatively small sample size, especially for neuroimaging.

Conclusions: Our study highlighted an influence of BPD neuropsychological impairments on symptomatology, and cortical thickness, prompting the potential clinical utility of a cognitive remediation program in BPD.