Early structural brain abnormalities in borderline personality disorder.

Background: Structural imaging studies of borderline personality disorder (BPD) have identified regions of reduced and increased cortical volume, as well as volume reductions in the hippocampus and amygdala, although with considerable variability across studies. Examining adolescent patients with the disorder can reduce potential confounding effects such as later development of affective and other comorbid disorders.

Methods: Fifty-one adolescents (48 females, 3 males) with BPD and without comorbid disorders and with 43 matched healthy controls underwent whole-brain voxel-based morphometry (VBM). Hippocampus and amygdala volumes were also measured using conventional volumetric techniques.

Results: At a threshold of p = 0.05 corrected, the BPD patients exhibited a cluster of grey matter volume reduction in the left temporo-parietal junction (TPJ). No evidence of volume reductions in the hippocampus or amygdala was found. Comparison between the female-only subsamples (48 BPD patients and 37 controls) yielded similar findings. The cluster of volume reduction in the left TPJ continued to be seen in 37 drug-naïve patients.

Conclusions: According to this study, the initial stage of BPD is characterized by decreased grey matter volume in the left TPJ, a region that is implicated in various aspects of social cognition. Given that the volume loss was detected prior to adulthood, in individuals without comorbidities, and among patients who were drug naïve, this finding could be significant for understanding the developmental trajectory of the disease.