Health & Medicine, Australia (Commonwealth Union) – Impressive findings have been seen in a trial of ketamine for severe depression may result in the treatment becoming more economical.
In a double-blind trial comparing it with a placebo, a cost-effective version of ketamine designed to treat severe depression has shown remarkable effectiveness.
Today, the British Journal of Psychiatry published research conducted by a team of researchers from The University of New South Wales (UNSW) and the affiliated Black Dog Institute, revealing that over 20 percent of the participants achieved complete remission from their symptoms after receiving bi-weekly injections for a month. Additionally, one-third of the participants experienced a significant improvement of at least 50% in their symptoms. The study was a collaborative effort involving six academic clinical mood disorder units in Australia and one in New Zealand, with funding support from the Australian National Health and Medical Research Council (NHMRC).
“For people with treatment-resistant depression – so those who have not benefitted from different modes of talk-therapy, commonly prescribed antidepressants, or electroconvulsive therapy – 20 per cent remission is actually quite good,” explained the lead researcher Professor Colleen Loo.
“We found that in this trial, ketamine was clearly better than the placebo – with 20 per cent reporting they no longer had clinical depression compared with only 2 per cent 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.”
The researchers enrolled 179 individuals who were suffering from treatment-resistant depression. Each participant received an injection, with some receiving a generic form of ketamine, widely used in Australia for anesthesia and sedation, while others received a placebo. The injections were administered twice a week at a monitored clinic, where the participants were observed for about two hours until the acute dissociative and sedative effects of the injection wore off, which typically occurred within the first hour. The treatment period lasted for one month, and the participants were asked to evaluate their mood at the end of the trial and again after one month.
To maintain a double-blind trial design and minimize psychological biases, both the participants and the researchers administering the injections were unaware of which individuals received the generic ketamine and which ones received the placebo. It was essential to choose a placebo that also induced sedation to improve the effectiveness of the treatment masking. Instead of using saline, which was common in many previous studies, a sedative called Midazolam, typically administered before general anesthesia, was chosen as the placebo for this trial.
According to Professor Loo, in previous studies, it became evident who received ketamine and who received the placebo because the saline used as a placebo did not produce any subjective effects.
Professor Loo further indicated that the application of midazolam, that does not treat depression, however it makes you feel a bit dizzy and out of it, where the individual has a lower chance of being aware if you got ketamine with similar acute effects.
The recent trial stood out from previous studies in several ways, one of which was its inclusion of individuals who had undergone electroconvulsive therapy (ECT) in the past.
Professor Loo indicated that individuals receive ECT treatment recommendations for depression when every other treatment has not shown the desired results.
She further indicated that in a majority of studies individuals who have ECT are excluded as it is difficult for the treatment to be effective when ECT has failed.
An additional distinct aspect of this trial was the subcutaneous administration of the drug instead of using a drip, significantly reducing both the time required and the medical complexity. Furthermore, this study holds the distinction of being the largest in the world to date, comparing generic ketamine against a placebo in the treatment of severe depression.
