[imagesource:emottawablog]
Over the last 20 years, the antidepressant effects of ketamine have been well-researched, however, most of the published research has been concerned with the injectable or nasal spray versions of the drug.
A new clinical trial has now shown that slow-release, twice-a-week ketamine tablets significantly reduced depression symptoms.
This opens the door for the possible treatment of severe depression using a simpler form that can be administered at home without medical supervision.
“The kind of results we’re seeing look as good as other ways of giving ketamine and are fascinating for two reasons,” said Professor Colleen Loo, a clinical psychiatrist and researcher with the University of New South Wales Sydney (UNSW Sydney) and the Black Dog Institute (BDI). Loo has previously contributed to research on the injectable and nasal spray versions of ketamine as a treatment for depression.
“Rather than having to come to the clinic and have an injection and have medical monitoring for two hours, once or twice a week, this is much more convenient and allows patients to have their treatment at home, making it as convenient as other antidepressant medications.”
While not all patients respond the same to one approach, researchers are excited about the possibility of being able to offer different approaches to the treatment of depression. The trial’s findings also further the understanding of how ketamine works to treat depression.
“There’s one school of thought that says dissociative effects – where you’re feeling a kind of altered reality and perception – are actually integral to the ability to improve the depression with ketamine.”
“And that’s very similar to the psychedelic-assisted therapy model that says changing your brain circuit functioning in that very profound way gives you new insights that help you to break out of your way of thinking, and that this acute kind of dissociative altered reality experience is necessary for you to improve.”
The new approach, however, removes the ‘dissociative’ effects of the drug due to the slow release, yet patients still improve without suffering any ‘altered reality and perception’.
Loo believes this might disprove the theory that you must have these ‘altered reality perceptions’ to improve.
Professor Paul Glue of the University of Otago in New Zealand led the Phase 2 randomised controlled study, which was carried out in partnership with researchers from UNSW Sydney, BDI, and other Australian and New Zealand academic institutes.
As with any psychedelic medication, including injectable and nasal spray ketamine preparations, there are concerns regarding misuse. The researchers addressed this issue directly in the published paper.
“The extended-release ketamine tablets used in this study are exceptionally hard and difficult to shatter,” they said. “This property may make this formulation less likely to be diverted for abuse, due to difficulty in manipulation of the tablets. We were not aware of any participants reporting craving for the tablets, and only one participant was removed from the study for lack of compliance.”
Despite the promising results, the availability of a slow-release ketamine tablet as a treatment for depression is likely years away.