Metabolic Alterations in the Amygdala in Borderline Personality Disorder: A Proton Magnetic Resonance Spectroscopy Study

Abstract

Emotional dysfunction in a frontolimbic network has been implicated in the pathophysiology of borderline personality disorder (BPD). The amygdala is a key region of the limbic system and plays an important role in impulsivity, affect regulation, and emotional information processing and thus is likely related to BPD symptoms. Alterations of the metabolism in the amygdala might be of interest for understanding the pathophysiology of BPD. However, the amygdala is a difficult region from which to acquire magnetic resonance spectra. We implemented a method for proton magnetic resonance spectroscopy ((1)H MRS) at 3.0 T in which we acquire data within only the small amygdala. The purpose of this study was to determine alterations of the metabolism in the amygdala in BPD patients. Twenty-one unmedicated BPD patients and 20 age-matched healthy control participants underwent (1)H MRS to determine neurometabolite concentrations in the left amygdala. All participants underwent psychometric assessments. Significantly reduced total N-acetylaspartate (tNAA) and total creatine (tCr) concentrations in the left amygdala of patients with BPD were found. BPD patients with comorbid posttraumatic stress disorder (PTSD) showed lower levels of tCr compared with BPD patients without PTSD and healthy control subjects. No significant correlations between neurochemical concentrations and psychometric measures were found. Decreased tNAA and tCr might indicate disturbed affect regulation and emotional information processing in the amygdala of BPD patients. These findings are consistent with many functional and structural neuroimaging studies and may help to explain the greater emotional reactivity of BPD patients.