First Large-Scale Study Shows Ketamine Is a Powerful Antidepressant

A survey of 41,000 patients taking ketamine for pain found they were half as likely to show symptoms of depression compared to those not consuming the drug.

Ketamine, a hallucinogen that goes by the street name Special K, has emerged as one of the hottest new treatments for depression for a key reason: It works incredibly quickly, alleviating symptoms in just a few hours.

Other drugs used to treat depression generally take 2-4 weeks.

Yet despite the hype, concern about the potential abuse of the popular club drug has kept ketamine from ever receiving a large-scale clinical trial as an anti-depressant. Evidence of its effectiveness has been gleaned from small studies of 100 patients or less.

Today, however, researchers revealed a new, indirect approach to studying the impact ketamine has had on thousands of users.

The new study looked at 41,000 patients taking ketamine for pain and found they were half as likely to show symptoms of depression — suggesting that, in addition to working quickly, ketamine is also highly effective among patients for whom other drugs have proven ineffective.

"Current FDA-approved treatments for depression fail for millions of people because they don't work, or don't work fast enough," said the senior author of the study, Ruben Abagyan, professor at the Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California San Diego. "This study extends small-scale clinical evidence that ketamine can be used to alleviate depression, and provides needed solid statistical support for wider clinical applications and possibly larger scale clinical trials.”

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Ketamine was approved for use as a painkiller by the US Food and Drug Administration (FDA) in 1970, and given to wounded American soldiers during the Vietnam War.

But as a cousin of the drug PCP (phencyclidine), ketamine can produce euphoria and extreme visual and auditory hallucinations when taken in large doses. The result can be deadly, including from accidents or suicide while intoxicated.

The new study used the novel approach of retroactively mining the FDA Adverse Effect Reporting System (FAERS) database for symptoms of depression reported by patients taking ketamine or other drugs for pain.

The FAERS electronic system receives complaints and monitors problems registered by physicians, pharmacists, and patients about drugs that have been approved for use among the general public. In this case, however, researchers looked for the lack of depressive symptoms, rather than the presence of adverse side effects.

Using the FAERS data, the team found that the incidence of depression among patients taking ketamine was 50 percent lower than among patients taking any other drug or combination of drugs for pain.

That result also suggests ketamine may be one of the most effective antidepressant treatments available. Meta-analyses of randomized control trials typically report antidepressants to be only 20 to 30 percent more effective than taking a placebo.

More than 300 million people worldwide suffer from depression, according to the World Health Organization.

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