Glutamatergic and GABAergic Mediators of Antidepressant Response in Major Depression

Primarily, this study seeks to evaluate whether citalopram treatment is associated with an increase in the Glutamine (Gln)/Glutamate (Glu) ratio in the anterior cingulate cortex (ACC) from baseline to day 3 of treatment. Additionally, this study would like to examine whether citalopram treatment is associated with an increase in the Gln/Glu ratio in the ACC from baseline to day 7 of treatment. In order to more fully examine baseline neurochemical and functional abnormalities in participants with MDD, we also seek to scan a group of age- and sex-matched non-depressed comparison individuals in order to perform between-group analyses of baseline neuroimaging measures.