Why this study matters

Up to 30% of patients with depression do not have a satisfactory response to pharmacologic treatment, and are thus considered to be treatment-resistant.

Although both pharmacologic (aripiprazole, quetiapine, olanzapine–fluoxetine combination, and brexpiprazole) and non-pharmacologic treatments (transcranial magnetic stimulation, vagus nerve stimulation, and ECT) are approved for patients with TRD, there continues to be a need for safe and effective treatment options.

Subanesthetic infusions of ketamine can be administered in the outpatient setting. Ketamine has a rapid onset, is effective in ameliorating symptoms for days, and the efficacy does not decrease with repeated use.

Study design

A meta-analysis was conducted involving patients with TRD in 116 studies (n=4615 patients) to determine response and remission following ketamine treatment.

Results and conclusion

Of patients with TRD who were treated with ketamine, 45% responded and 30% remitted. Unlike response to ketamine, patients who were had greater treatment-resistance remitted less often. Repeated treatment with ketamine did not diminish efficacy.