Ketamine Associated ACC GABA and Glutamate Change and Depression Remission:

This is a feasibility study and the goal of this project is to evaluate whether peak ACC GABA and glutamate, quantified as a CSF-corrected absolute concentration percent change from baseline, is associated with clinical remission, Montgomery Asberg Depression Rating Scale (MADRS) total score of \<10, to the anti-glutamatergic antidepressant ketamine. As MRS is expensive, we also aim to study a correlation between change in peripheral metabolites (GABA and glutamate) and central GABA and glutamate levels.