The investigators propose applying a previously validated computational model of the MMN and the ensuing effects of NMDAR antagonism to predict treatment response following ketamine infusions in TRD patients and distinguish ketamine's antisuicidal effects from those related to mood improvements. The study has two subgoals: first, the computational mechanisms underlying MMN reductions that predict ketamine treatment response in TRD patients will be examined. Second, the computational mechanisms will be linked to their underlying neural causes using neural circuit models. Beyond understanding ketamine's short- and long-term mechanisms of action in TRD, the parameters obtained from fitting these models to noninvasive EEG recordings may facilitate single-patient treatment predictions. If successful, this approach may provide clinically useful prognostic statements in individual patients.
To develop and test a neurocomputational model of ketamine treatment response predictions in TRD.