Rapid Antidepressant Effect of Ketamine Anesthesia During Electroconvulsive Therapy of Treatment-Resistant Depression

Reports of the superiority of the antidepressant effect of ketamine during the conduct of electroconvulsive therapy (ECT) have been limited. We conducted an open-label trial of ketamine to determine whether ketamine as the anesthetic during ECT would provide a greater antidepressant effect than the antidepressant effect obtained with propofol.Between April 2006 and April 2007, 31 inpatients with treatment-resistant depression gave written consent for ECT and to participate in this study. An anesthesiologist who was unaware of the mental symptoms of the subjects assigned them to receive propofol or ketamine anesthetic according to the preferences of the patients, and the patients underwent 8 ECT sessions for 4 weeks. The Hamilton Depression Rating Scale (HDRS) was valuated before ECT and after the completion of the second, fourth, sixth, and eighth ECT sessions.The HDRS scores improved earlier in the ketamine group, with decreases in HDRS scores that were significantly greater in the ketamine group.The results suggested that it is possible to improve symptoms of depression earlier by using ketamine anesthesia.