Metabolomic signatures of intravenous racemic ketamine associated remission in treatment-resistant depression: A pilot hypothesis generating study.

In this pilot study (N = 9), we highlight new insights gained on ketamine's mechanism of action where we have mapped biochemical processes that are affected within 40 min of intravenous ketamine exposure. Targeting acylcarnitines, we demonstrated rapid utilization of short-chain acylcarnitines within 40 min of ketamine treatment followed by restoration within 24 h; this change in short chain acylcarnitine with rapid-acting antidepressant treatment is consistent with previous work identifying similar change but at 8-weeks with slower-acting SSRI treatment. Using a non-targeted metabolomics platform, we defined broader effects of ketamine on lipid metabolism and identified changes in triglyceride that correlate with ketamine response. This study provides novel insights into ketamine's action and highlighting a possible role for mitochondrial function and energy metabolism in ketamine's mechanism of action.