Abnormalities in gray matter volume in patients with borderline personality disorder and their relation to lifetime depression: A VBM study

Abstract

Background: Structural imaging studies of borderline personality disorder (BPD) have found regions of reduced cortical volume, but these have varied considerably across studies. Reduced hippocampus and amygdala volume have also been a regular finding in studies using conventional volumetric measurement. How far comorbid major depression, which is common in BPD and can also affect in brain structure, influences the findings is not clear.

Methods: Seventy-six women with BPD and 76 matched controls were examined using whole-brain voxel-based morphometry (VBM). The hippocampus and amygdala were also measured, using both conventional volume measurement and VBM within a mask restricted to these two subcortical structures. Lifetime history of major depression was assessed using structured psychiatric interview.

Results: At a threshold of p = 0.05 corrected, the BPD patients showed clusters of volume reduction in the dorsolateral prefrontal cortex bilaterally and in the pregenual/subgenual medial frontal cortex. There was no evidence of volume reductions in the hippocampus or amygdala, either on conventional volumetry or using VBM masked to these regions. Instead there was evidence of right-sided enlargement of these structures. No significant structural differences were found between patients with and without lifetime major depression.

Conclusions: According to this study, BPD is characterized by a restricted pattern of cortical volume reduction involving the dorsolateral frontal cortex and the medial frontal cortex, both areas of potential relevance for the clinical features of the disorder. Previous findings concerning reduced hippocampus and amygdala volume in the disorder are not supported. Brain structural findings in BPD do not appear to be explainable on the basis of history of associated lifetime major depression.

Fig 1. Whole-brain VBM comparison of the BPD patients and controls.

Cluster of volume reduction in BPD located in medial frontal cortex and in lateral frontal cortex. The right side of the image is the right side of the brain. Slice labels from left to right z (MNI) = 23 -17 -13 -8 2 4.

Fig 2. Scatter plots of correlations between: a) mean volume in the combined lateral frontal region and BSL-23 scores, b) mean volume in the medial ROI and BSL-23 scores.

Fig 3. Clusters of increased volume on VBM within the bilateral hippocampus/amygdala mask (mask shown in green).

Increased gray matter volume in right amygdala (p = 0.02) and right hippocampus (p = 0.03) is shown in yellow. The right side of the image is the right side of the brain. Slices labels: z (MNI) -22 -20 -18 -16.