Scientists are working on what could be a brand new way to treat depression using lessons learned from a drug with a reputation as a party drug: ketamine.

Ketamine is meant to be a rapid-acting anesthetic used by veterinarians, but it’s become a popular recreational drug that goes by such nicknames "Vitamin K," "Kit Kat," or simply "K," because it can bring on hallucinations, a feeling of weightlessness, or "out-of-body" experiences.

Now scientists are looking at ketamine in a new way, saying it may have a new and powerful use as an antidepressant that can lift even chronic depression in just hours.

If the drug’s power can be harnessed, it could mark a major improvement over current antidepressant medications, which typically take weeks -- or even months -- to work.

Many antidepressants currently in use work by increasing levels of "feel-good" hormones such as serotonin. But ketamine appears to target the glutamate system in the brain, which governs the brain cells that control mood.

"By acting on the glutamate system, you produce a cascade an effect on other systems that can have a beneficial action on the treatment of depression," Dr. Pierre Blier, a researcher at the University of Ottawa Institute of Mental Health Research, tells CTV News.

Studies are showing the drug has an effect in about 70 per cent of patients within a day, though around a third of patients see no result.

At the Royal Ottawa Hospital, doctors have started using ketamine as a drug of last resort -- delivered intravenously to some patients rushed to the emergency department because of suicidal thoughts.

While the drug can be effective, there are drawbacks: the effects sometimes last only about a week and there is the risk the drug will bring on hallucinations.

So doctors are now testing other drugs designed to work like ketamine.

The U.S. National Institutes of Health is working on an experimental agent, called AZD6765, which also acts through the brain's glutamate chemical messenger system. It, like ketamine, works by blocking glutamate binding to a protein on the surface of neurons, called the NMDA receptor.

Researchers at Northwestern University are also studying a similar drug called GLYX-13, which also targets NMDA receptors.

They recently conducted a study in which they gave the drug to 116 people with depression who did not respond to other treatments. While it wasn’t effective in all patients, it performed significantly better than the placebo, with no significant side effects.

Now, the move is on to conduct further studies, to test whether repeated or high doses a few times per week might produce longer-lasting results across more patients, giving doctors a new tool in the fight against depression.