Increased ratio of glutamate/glutamine to creatine in the right hippocampus contributes to depressive symptoms in patients with epilepsy.

Purpose: Our study aimed to investigate whether the glutamatergic system in the hippocampus is correlated with depressive symptoms in patients with epilepsy.

Methods: Fifty patients with epilepsy were recruited and divided into three groups on the basis of their Hamilton Depression Rating Scale (HAMD) scores. Single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) was carried out. Pearson correlation analysis and multiple linear regression analysis were performed to investigate any correlation between the variables of hippocampal metabolites and HAMD scores.

Results: Proton magnetic resonance spectroscopy analysis showed that the ratio of glutamate/glutamine to creatine (Glx/Cr) in the right hippocampus was significantly increased in patients with moderate depression and correlated positively with HAMD scores. Multiple linear regression analysis showed that the ratio of Glx/Cr in the right hippocampus was an independent risk factor relating to depressive symptoms in patients with epilepsy.

Conclusion: A disturbance of the hippocampal glutamatergic system may be involved in the pathogenesis of depression in epilepsy.