Ketamine is as effective as electroconvulsive therapy for non-psychotic patients with treatment-resistant major depression, results from a head-to-head trial show.

US psychiatrists say 55% of participants given IV ketamine had self-reported improvements in depressive symptoms compared to 41% of those assigned to electroconvulsive therapy (ECT), showing the anaesthetic was non-inferior.

Both interventions also led to improved quality of life immediately after the initial three-week treatment phase, say researchers led by the Brigham and Women’s Hospital in Boston.

The team assigned 365 patients (mean age 46) with treatment-resistant major depression without psychosis to receive either IV ketamine 0.5mg/kg of body weight over 40-minute sessions twice weekly or right unilateral ECT sessions three times a week.