Correlation of glutamate levels in the anterior cingulate cortex with self-reported impulsivity in patients with borderline personality disorder and healthy controls.

CONTEXT: Dysfunction and deficits in the structure of the anterior cingulate cortex have been reported in borderline personality disorder (BPD). To our knowledge, there is only 1 published study to date investigating anterior cingulate cortex metabolism in subjects with BPD and co-occurring attention-deficit/hyperactivity disorder using proton magnetic resonance spectroscopy. Impulsivity is a key feature of BPD and can be related to anterior cingulate cortex function.

OBJECTIVE: To investigate whether anterior cingulate cortex metabolism may be altered in BPD and correlates with BPD pathology.

DESIGN: Cross-sectional proton magnetic resonance spectroscopy study.

SETTING: Department of Psychosomatic Medicine and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany.

PARTICIPANTS AND PATIENTS: Thirty unmedicated female subjects meeting DSM-IV criteria for BPD and 31 age-matched healthy female control participants.

MAIN OUTCOME MEASURES: Neurometabolite concentrations in the anterior cingulate cortex and correlation of glutamate levels with self-reported measures of impulsivity and severity of borderline symptoms.

RESULTS: Significantly higher levels of glutamate in the anterior cingulate cortex were found in subjects with BPD as compared with healthy controls. A positive correlation between glutamate concentration and the Barratt Impulsiveness Scale total score as well as between glutamate concentration and the subscore for cognitive impulsivity were observed irrespective of diagnosis. We also found a positive correlation between glutamate concentrations and dissociation as well as between glutamate concentration and subscores of the Borderline Symptom List in the patient group.

CONCLUSIONS: Our results support the hypothesis that higher glutamate concentration in the anterior cingulate cortex is associated with both severity of BPD symptoms and subjective impulsivity ratings, the latter independent of BPD. Further studies should confirm the association between enhanced glutamate concentration in the anterior cingulate cortex and behavioral measures of impulsivity.