The anesthetic agent ketamine has a fast-acting antidepressant effect, but that doesn't improve the response to electroconvulsive therapy (ECT) for severe depression, according to a study in the September issue of The Journal of ECT, official journal of the International Society for ECT and Neurostimulation. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.
The study did not show the "robust rapid antidepressant response" to ketamine reported in previous studies—perhaps because ketamine was used in combination with a different type of anesthetic. The research was performed by Dr. Gerard Sancora and colleagues of Yale University School of Medicine.
Ketamine Has Rapid Antidepressant Effect…
Recent studies have suggested that ketamine brings rapid improvement in patients with severe depression. In contrast to standard antidepressants, which can take weeks to months to have an effect, a single injection of ketamine improves symptoms within a few hours.
Electroconvulsive therapy is a highly effective treatment for severe depression, but repeated treatments are generally needed to bring improvement. Ketamine might help to bridge the gap before ECT takes effect. "Interestingly, ketamine has been used in ECT anesthesia for decades," the researchers note.
The study included 18 patients with episodes of major depression who were scheduled for ECT after not responding to standard antidepressant drugs. All patients received a drug called thiopental to provide anesthesia for ECT. One group received a low dose of ketamine in addition to thiopental. The ketamine dose was "subanesthetic"—lower than needed to produce anesthesia.
…But Doesn't Enhance Response to ECT for Major Depression
The study was stopped early when preliminary results showed no improvement in the response to ECT with ketamine. Depression scores improved in both groups; it generally took six ECT treatments over two weeks to show an effect.