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

► We conducted a meta-analysis on 1H-MRS-findings in major depressive disorder (MDD). ► Glutamate and Glx concentrations are lower in the anterior cingulate cortex in MDD. ► Glx is decreased in all brain regions together in current episode patients. ► Whether glutamate changes in MDD are indeed state-dependent needs confirmation.