Regional cortical thinning may be a biological marker for borderline personality disorder.

OBJECTIVE: We investigated cerebral cortical thickness and its relation to measurements of difficulties with identifying and describing emotions in patients with borderline personality disorder (BPD).

METHOD: Eighteen SCID-II-diagnosed female patients with BPD and 21 healthy female controls underwent magnetic resonance imaging and completed the Toronto Alexithymia Scale (TAS). First, regional cortical thickness across the cerebral surface was compared between patients and healthy controls. Then, analyses of the association between cortical thickness and TAS subscales were performed in patients.

RESULTS: Compared with controls, patients exhibited clusters of significantly reduced cortical thickness in the left medial and lateral prefrontal cortex, left temporoparietal junction, bilateral temporal poles, and bilateral paracentral lobules. Significant negative associations were observed between cortical thickness and the 'Difficulties Describing Feelings' TAS subscale (DDF) scores in patients. The anatomical distribution of these associations was highly overlapping with the group differences in cortical thickness.

CONCLUSION: The pattern of regions exhibiting cortical thinning in patients resembles a network of cortical structures repeatedly shown to be involved in social cognition. The results of the DDF analyses suggest that the thinning may partly be related to interpersonal dysfunction in patients with BPD. The pattern of thinning may represent a potential biological marker for BPD.