Comparative Efficacy of Ketamine in Treatment-Resistant Depression

Patients unresponsive to two antidepressant trials are considered to have treatment-resistant depression (TRD). A review of open-label studies found that various pharmacological and brain stimulation treatments produce similar response rates of 30% to 70% and remission rates of 20% to 50%. In randomized placebo-controlled trials, response rates ranged from 15% to 60% and remission rates from 10% to 40%. Ketamine and electroconvulsive therapy achieve rates at the higher ends of these ranges, with the advantage of rapid action in acute settings. Direct comparative studies with large samples are needed to determine if one treatment offers greater benefit.

Study at a glance

Abstract

Patients who have not responded to two antidepressant trials in their current depressive episode are usually considered to have treatment-resistant depression (TRD). A detailed search on PubMed was conducted for reported response and remission rates for non-ketamine and ketamine treatments for TRD. From a variety of pharmacological and brain stimulation open-label studies, the treatments were found to have similar response and remission rates of 30% to 70% and 20% to 50%, respectively. For randomized placebo-controlled trials, reported response and remission rates were 15% to 60% and 10% to 40%, respectively. Ketamine and electroconvulsive therapy both have response and remission rates at the higher end of these ranges, and their significant advantage is their fast action in an acute setting. Direct comparative efficacy studies with large sample sizes will be needed to establish any margin of increased benefit of one treatment modality compared to the other. [ Psychiatr Ann . 2020;50(2):62–67.]