Researchers at Yale have discovered the utterly fascinating way that ketamine, a medication usually used as a general anesthetic in children, and a drug of abuse for some adults, fights depression. Their findings were published in the journal Science

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Ketamine works by rapidly repairing and establishing new connections between brain cells that were damaged by stress. It does so with such rapidity that a very large percentage of patients experience relief from major depression within hours, not the usual weeks or months that other antidepressants require. The effects of a single dose can last a week or 10 days. And ketamine works on 70 percent of patients for whom no other psychiatric antidepressant has been effective.

Ketamine has also been proven to rapidly diminish or entirely stop suicidal thinking in depressed patients.

This is startling, tremendously hopeful information. True, ketamine in its present form must be administered intravenously under medical supervision. It also can trigger short-term serious side effects, including psychotic thinking and hallucinations. And, obviously, no one should take ketamine to get high. But it is now time to look into how ketamine can be deployed in psychiatric settings where millions of people suffer with intractable, debilitating depression that might well yield to this medicine.

Ketamine can provide windows of hope on the future for people who have struggled and seen only darkness for months or years. There is no reason to withhold it from the clinical population that might benefit most from it, and I believe the FDA should fast-track an approval for ketamine in specific populations.

Depression is as much a scourge as heart disease, and patients in the throes of it can be in excruciating psychological (and sometimes physical) pain. If we had a medication at hand that could stop unbearable cardiac pain for a week at a time, we'd start deploying it in hospitals everywhere. This moment should be no different.

Potentially even more important than the discovery that ketamine works as well as it does, Yale researchers were also able to identify the chemical pathway and a key enzyme involved in the way that ketamine restores connections between brain cells. This enzyme, called mTOR, is critical in the synthesis of a protein nerve cells need to repair the fluid-filled "touch points," called synapses, at which they exchange chemical messengers.

We should be funding research into the psychiatric benefits of other drugs that human beings have abused or been drawn to for "recreation." That research should look, for example, at the ways that opiates decrease anxiety (and might be chemically altered to do so even more powerfully) and the way that nicotine impacts depression and weight gain and even the reasons why those who chronically abuse laxatives swear that they feel steadier emotionally.

Asking whyis the key to discoveries that change things for the better.

If you or someone you love has suffered with chronic, unremitting depression or very severe depression that now includes suicidal ideation, press your psychiatrist to seriously consider procuring ketamine and using it.

Dr. Keith Ablow is a psychiatry correspondent for Fox News Channel and a New York Times bestselling author. His book, "Living the Truth: Transform Your Life Through the Power of Insight and Honesty" has launched a new self-help movement includingwww.livingthetruth.com. Dr. Ablow can be reached atinfo@keithablow.com.

Dr. Keith Ablow is a psychiatrist and member of the Fox News Medical A-Team.