Ketamine infusions improve symptoms of depression and anxiety, study says

People who received intravenous ketamine at three private ketamine infusion clinics had “significant improvement” in symptoms of depression, anxiety and suicidal ideation, a new study says.

O study, published on Monday (12) in the Journal of Clinical Psychiatryadds to a growing body of research showing the promise of ketamine in treating these conditions.

It “provides some more real-world data, which is incredibly important” because it helps show its potential to work in a more general population, said Dr. Gerard Sanacora, professor of psychiatry at the Yale School of Medicine in the United States.

But the study leaves some critical gaps, including data on adverse effects and direct comparisons with other options, that make it difficult to conclude how it should be used, he said.

Ketamine is a powerful drug used in hospitals primarily as an anesthetic. It is also used illegally as a club drug that creates an intense, dissociative effect. As it is not approved to treat depression and is therefore used for that purpose “off-label” [fora das condições aprovadas]is not covered by insurance, even when recommended by a doctor.

The study

The researchers analyzed data from 424 people with treatment-resistant depression who were treated between November 2017 and May 2021 at three ketamine infusion clinics in Virginia that specialize in people with suicidal ideation, depression or anxiety.

During each clinic visit, patients completed physical and mental health surveys. Patients received six infusions over 21 days.

Within six weeks of starting the infusions, the researchers say, half of the participants responded to treatment and 20% had depressive symptoms in remission. After 10 infusions, response and remission rates were 72% and 38%, respectively.

Half of the patients who had suicidal ideation were in remission after six weeks, and there was a 30% reduction in anxiety symptoms over the course of treatment, according to the study.

Response rates in the initial phase of treatment were similar to those of oral medication and transcranial magnetic stimulation for treatment-resistant depression, the researchers say.

Remission rates were on par with transcranial stimulation but were not as helpful as optimized trials of electroconvulsive therapy, which can be more expensive and carry additional risks.

Research limitations include that it was not a blinded study with a control group. He did not look at people who refused infusions and relied on self-reported research.

The researchers also note that they have not systematically evaluated the side effects or adverse events of treatment, but previous studies have found no permanent or long-term side effects on memory or cognitive decline.

The lack of information about adverse effects is “disappointing,” Sanacora said. Ketamine comes with a “unique set of risks, both for the individual and for society,” including the potential for drug abuse and unknown effects from frequent use, especially at higher levels.

But without the adverse effects data — and without comparing the results to a control group or not, it’s hard to know how to weigh the benefits against the risks.

“My point is that I think this is an incredibly important treatment to add to our arsenal to combat serious mood disorders and psychiatric illnesses, but we have to use it responsibly and carefully,” he said.

In 2019, the US Food and Drug Administration approved a nasal spray that uses esketamine, a cousin of ketamine, for treatment-resistant depression.

The researchers of the new study say that racemic ketamine infusions (which use two forms of ketamine molecules, in contrast to the single form of esketamine) are cheaper than escetamine and could result in savings if covered by insurance.