Comparing the effects of ECT and intravenous ketamine in psychiatric patients with major depressive episodes

Electroconvulsive therapy (ECT) and intravenous (IV) ketamine are treatments used for severe depression and/or treatment-resistant depression (TRD). ECT is considered one of the most effective treatments for severe depression, although there is debate within the field regarding the effectiveness between ECT and IV ketamine in comparable TRD patient groups.

This retrospective chart review of open-label, nonrandomized treatment from a psychiatric hospital compared the effects of up to three weeks of ECT and IV ketamine in patients with major depressive episodes (MDEs). Our cohort included 146 inpatients and outpatients aged 18 to 74 years old. 94 patients received subanesthetic IV ketamine infusions 2 times a week, and 52 patients received ECT treatment 2-3 times a week. The primary outcome measure was the Montgomery-Asberg Depression Rating Scale (MADRS).

Overall on the MADRS, 45.2 % of participants showed clinical symptom change between the beginning of treatment compared to the end of treatment, while 54.8 % did not. Reliable change index (RCI) analysis indicated 58.9 % showed significant symptom change, while 41.1 % did not. Chi-Square tests revealed significant associations between treatment type and clinical symptom change on the MADRS, with patients who received ECT showing greater symptom improvement compared to those who received ketamine (p < .05). Response rates of ECT and ketamine were 67.3 % and 45.7 %, respectively, whereas remission rates for ECT and ketamine were 60.0 % and 46.1 %, respectively.

ECT demonstrated the more robust antidepressant effects compared to ketamine. Randomized comparative trials are required to gain a better understanding of these modalities.