According to researchers in Australia, the anesthetic and recreational drug ketamine could be effective in preventing suicide and lifting mood in people who are severely depressed in a way they describe as “game-changing.” They report the results of the pilot trial in The World Journal of Biological Psychiatry.

The results show that the drug known on the streets as ‘special K,’ was effective – at least temporarily – for most trial participants, who were all patients with major depressive disorder and who had exhausted all other treatments.

Lead author Colleen Loo is a professor at the University of New South Wales in Sydney, where she specializes in psychiatry and neurosciences. She describes the finding as a “game-changer in treating depression,” and says:

“The real advantage here is that the effect is almost instantaneous and that it appears to work on the majority of patients.”

Current drugs for depression can take up to 8 weeks to reach full effect. Also, it is not easy to match the right drug to the right patient, which has to be done by trial and error.

“This could be of real benefit if a patient is suicidal, as it could help yank them out of that really dark place,” says Prof. Loo, who also explains how ketamine works:

“Ketamine powerfully reverses structural changes in the brain that occur when someone is depressed. In a sense, the treatment is repairing or reversing those changes.”

The purpose of the pilot trial was to determine an appropriate dose rate for the drug. Previous studies have already established that ketamine potentially has impressive antidepressant effects, but nobody had yet determined how best to administer it or find the relationships between dose, antidepressant response and adverse effects.