Injection Ketamine effective for treatment-resistant depression

A low-cost version of ketamine to treat severe depression has performed strongly in a double-blind trial that compared it with a placebo.

In research published in the British Journal of Psychiatry, researchers led by UNSW Sydney and the affiliated Black Dog Institute found that more than one in five participants achieved total remission from their symptoms after a month of bi-weekly injections, while a third had their symptoms improved by at least 50 percent.

The researchers recruited 179 people with treatment-resistant depression. All were given an injection of either a generic form of ketamine that is already widely available in Australia as a drug for anesthesia and sedation – or a placebo. Participants received two injections a week in a clinic where they were monitored for around two hours while acute dissociative and sedative effects wore off – usually within the first hour. The treatment ran for a month and participants were asked to assess their mood at the end of the trial and one month later.

Lead researcher Professor Colleen Loo says, “We found that in this trial, ketamine was clearly better than the placebo – with 20 percent reporting they no longer had clinical depression compared with only 2 percent in the placebo group. This is a huge and very obvious difference and brings definitive evidence to the field which only had past smaller trials that compared ketamine with placebo.”

Reference: Efficacy and safety of a 4-week course of repeated subcutaneous ketamine injections for treatment-resistant depression (KADS study): randomized double-blind active-controlled trial, The British Journal of Psychiatry, DOI 10.1192/bjp.2023.79