Biomarkers of Fast Acting Therapies in Major Depression

Approved FDA indications for ketamine include use as an adjunct in the induction and maintenance of general anesthesia and for procedural sedation. For general anesthesia, ketamine is given at dosages ranging from 1-2mg/kg and given either as bolus injection or run continuously (0.1 to 0.3mg/kg/min) in conjunction with another anesthetic or sedation agent. In this study, ketamine at a subanesthetic dose of 0.5mg/kg will be diluted in 60cc of normal saline and administered via a slow IV infusion over 40 minutes at each treatment session in patients while undergoing hemodynamic monitoring. When used in this manner, ketamine infusion does not induce general anesthesia or states of unconsciousness, and patients remain fully awake, responsive to commands, and do not lose respiratory drive.