Region and state specific glutamate downregulation in major depressive disorder: A meta-analysis of 1H-MRS findings

J. J. Luykx*, K. G. Laban, M. P. van den Heuvel, M. P.M. Boks, R. C.W. Mandl, R. S. Kahn, S. C. Bakker

*Corresponding author for this work

Research output: Contribution to journalReview articleAcademicpeer-review

Abstract

For major depressive disorder (MDD), magnetic resonance spectroscopy ( 1H-MRS) studies of glutamate, glutamine and Glx (the composite measure of mainly glutamate and glutamine) have yielded inconclusive or seemingly inconsistent results. We therefore systematically reviewed whether in vivo concentrations of glutamate, glutamine and Glx measured with 1H-MRS differ between MDD patients and controls. Meta-analysis including meta-regression, sensitivity, statistical heterogeneity, and publication bias analyses were conducted. Glutamate and Glx concentrations were found to be lower in the anterior cingulate cortex (ACC) in patients compared to controls (standardized mean difference (SMD) for glutamate with 95% CIs: -0.86, -1.55 to -0.17; and for Glx: -1.15, -1.86 to -0.44). In addition, Glx was decreased in all brain regions together in current episode patients (SMD: -0.62, -1.17 to -0.07). We conclude that in MDD, glutamate and possibly glutamine are downregulated primarily in the ACC and during depressive states. These results fit the central role of the ACC in depressive symptomatology and suggest that in MDD changes in glutamatergic neurotransmission are state-dependent.

Original languageEnglish
Pages (from-to)198-205
Number of pages8
JournalNeuroscience and Biobehavioral Reviews
Volume36
Issue number1
DOIs
Publication statusPublished - 1 Jan 2012

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