Ketamine has been used successfully to treat severe depression in the US, CNN reports.

Ketamine use may be the biggest breakthrough in mental health in the past 50 years, comments Dr. Kevin Kane, a practicing anesthesiologist and Ketamine Milwaukee's medical director.

He estimates that it is effective for 70% of patients with treatment-resistant depression.

How ketamine works

Ketamine acts in hours, not days or weeks like traditional antidepressants. It works on a completely different part of the brain. Most other antidepressants act on the monoamine system of the brain, targeting serotonin or similar neurotransmitters explains Ketamine Milwaukee, the first clinic in Wisconsin dedicated to the safe administration of intravenous ketamine infusion therapy.

Ketamine is different as it targets a completely separate system - the glutamate system.Researchers have found that ketamine stimulates a molecule called Brain-Derived Neurotrophic Factor (BDNF), which has been coined with "Miracle-Gro for the brain" because it is associated with the growth of new branches on the nerve cells as well as more and better connections between the neurons. It makes nerves blossom like a tree in spring.

It is indicated right now for ... somebody who has tried and failed at least two medications, but that's really not what we're seeing, "Kane said, instead of patients who have tried more medications than they can count. Some of them have been depressed for as long as they can remember.

The ketamine is administered intravenously, and relief can come quickly - in just a matter of hours.

A patient's case

The efficacy of one of the patients' theatment - Alan Ferguson, is evident in a mood chart provided to CNN by Kane, with his patient's permission. The black lines indicate Ferguson's ketamine infusion dates, and the red dots are his scores on the PHQ-9 (a standardized depression questionnaire). On May 25, the day of his first infusion, Ferguson's depression was rated "severe."By his second infusion on June 1, it had improved to "moderate." And by his third infusion on June 8, for the first time in his adult life, Ferguson's depression rating measured "none."

Read more about ketamine HERE