Comparison of Rapid Antidepressant and Antisuicidal Effects of Intramuscular Ketamine, Oral Ketamine, and Electroconvulsive Therapy in Patients With Major Depressive Disorder

A pilot study randomly assigned 45 adults with major depressive disorder to receive either intramuscular ketamine (0.5 mg/kg), oral ketamine (1 mg/kg), or electroconvulsive therapy (ECT) over 3 weeks. Depression and suicidal ideation scores improved significantly in all groups, with no meaningful differences between the three treatments. Ketamine caused brief, transient dissociative symptoms, whereas ECT led to memory loss lasting up to a month in some patients. Patients who received ketamine preferred it over ECT. The authors suggest that oral and intramuscular ketamine may have antidepressant effects equal to ECT, with possibly greater antisuicidal effects, fewer cognitive side effects, and higher patient preference.

Study at a glance

Abstract

Abstract Purpose/Background This study was devised to compare the antidepressant and antisuicidal effects of oral and intramuscular (IM) ketamine versus electroconvulsive therapy (ECT). Methods/Procedures In our pilot study, 45 patients with major depressive disorder (based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria) in the age range of 18 to 70 years who were determined suitable candidates for ECT got randomly divided into 3 equal groups. Each group received one of these treatment modalities: 0.5 mg/kg of IM ketamine; 1 mg/kg of oral ketamine; and ECT in 6 to 9 sessions during 3 weeks. Depression and suicidal ideation scores were recorded using the Hamilton Depression Rating Scale and the Beck Scale for Suicidal Ideation, respectively, at baseline, 24 hours, 1 week, 2 weeks, and 3 weeks within the intervention. The measurements were repeated 1 week and 1 month after the end of the intervention as well. Vital signs and adverse effects were noted. Finally, satisfaction levels of patients for each method were recorded and compared between groups. Findings/Results The Hamilton Depression Rating Scale and the Beck Scale for Suicidal Ideation scores significantly improved in all groups compared with baseline with no significant differences between the 3 groups. The adverse effects for ketamine-consuming groups such as dissociative symptoms were brief and transient, whereas memory loss for the ECT group remained up to 1 month in some patients. Ketamine-receiving groups preferred it more than ECT. Implications/Conclusions Oral and IM ketamine probably have equal antidepressant in addition to more antisuicidal effects compared with ECT but had less cognitive adverse effects and higher preference by patients. Thereby, ketamine can be an alternative method in the treatment of patients with severe and/or suicidal MDD.