What using a club drug to treat depression reveals about the brain

Olivia Harris/Reuters

The most intriguing way of putting it is that a notoriously unpredictable and dangerous club drug may be the solution to depression.

Perhaps unsurprisingly, this isn't the entire story.



So why, in a review published late last week in Science, have researchers declared that findings on the effects of ketamine -- what the kids call "Special K" -- on the depressed brain are "the biggest breakthrough in depression research in a half century"?

Anyone who's experienced major depressive disorder, either personally or through a loved one, would understandably be excited about the news that taking ketamine can lift depression in mere hours in patients who are resistant to typical antidepressants. The commonly prescribed serotonin selective reuptake inhibitors (SSRIs) take weeks to kick in, if they end up working at all (they don't, for more than a third of depressed patients). It's during this painfully long waiting period that suicide, for two to twelve percent of patients, can begin to be seen as the quickest way out of the darkest depressions.

So yes, ketamine's potent and rapid effects seem downright miraculous, even though the relief it provides from depression only lasts seven to ten days. But researchers at the Yale School of Medicine have known this for a decade now. And the drug has actually been approved by the FDA for use as an injected anesthetic, albeit one with short-term, but psychologically intense, side-effects:

The psychological manifestations vary in severity between pleasant dream-like states, vivid imagery, hallucinations, and emergence delirium. In some cases these states have been accompanied by confusion, excitement, and irrational behavior which a few patients recall as an unpleasant experience. The duration ordinarily is no more than a few hours; in a few cases, however, recurrences have taken place up to 24 hours postoperatively. No residual psychological effects are known to have resulted.

What is new -- and legitimately exciting -- about all this is that scientists are beginning to realize that we may have been thinking about the depressed brain in the wrong way. The effects seen with ketamine suggest that the common explanations for depression -- that it's caused by a "chemical imbalance" in the brain, or by low levels of serotonin -- may not be what's really causing the disorder after all.