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15 papers
Research shows that ketamine and a related drug, esketamine, can lift depressive symptoms quickly for some people, especially those who did not get better with usual antidepressants. Short-term randomized trials and expert reviews report clear, often fast benefits after a single dose or a few doses, and esketamine (a nasal spray) is approved for some hard-to-treat depressions. At the same time, many studies are small or short. The fast benefit often fades after days to a few weeks, so patients commonly receive repeated treatments. Researchers still need better long-term safety data, clearer rules about dosing and maintenance, and more work to understand exactly how ketamine works in the human brain.
In a small, carefully controlled study, seven people with major depression each received a single low-dose ketamine infusion on one day and a saline infusion on another day, without anyone knowing which was which. People who got ketamine showed clear improvement in their depressive symptoms within three days, while those…
Researchers tested a single intravenous dose of ketamine in 73 people with major depression that had not gotten better with usual treatments. In a two-site, double-blind trial, people were randomly given either ketamine or an active placebo (the anesthetic midazolam). Twenty-four hours after the infusion, people who got ketamine were…
Researchers tested a nasal spray form of esketamine together with a newly started oral antidepressant in adults whose depression had not improved after trying at least two antidepressants. Over four weeks, people who got esketamine plus a new antidepressant had faster and larger drops in depression symptoms than those who…
A group of international mood-disorder experts reviewed the research on ketamine and esketamine for adults whose depression did not get better with usual antidepressants. They found that these drugs work differently from standard antidepressants and can lift symptoms more quickly for some people with treatment-resistant depression. However, the experts also…
Treatment-resistant depression means depression that does not get better after usual treatments. Scientists do not all agree on one clear definition, which makes it hard to know exactly how common it is or which treatments work best. Using the definition that regulators often use, about 30% of people with depression…
This paper is a careful review of research about treatment-resistant depression. The authors looked through medical studies to see how doctors define this kind of depression, what makes it hard to assess, and which treatments have been tried. They describe drug strategies like adding lithium or thyroid hormone, switching antidepressant…
Researchers ran a clinical trial that directly compared ketamine treatment with electroconvulsive therapy (ECT) in people whose major depression had not improved with other treatments and who did not have psychosis. The trial found that ketamine was “noninferior” to ECT, which means ketamine worked at least as well as ECT…
This paper is a clear review of how ketamine can lift severe depression quickly for some people and what we know about how it works in the brain. The authors say a single low-dose intravenous shot of ketamine can produce rapid and lasting antidepressant effects in people whose depression did…
This review explains how ketamine can lift depression symptoms much faster than standard antidepressants. Researchers describe the clinical results, how doctors usually give ketamine, and the brain changes it seems to cause. They also say that the treatment must be given carefully because small dose changes matter, the exact brain…
Researchers tested repeated subcutaneous (under-the-skin) injections of racemic ketamine in people whose depression had not improved after at least two antidepressant trials. People got injections twice a week for 4 weeks and neither participants nor the raters knew which drug they were getting. When the study allowed higher, response-guided ketamine…
Major depressive disorder is a serious illness. Researchers reviewed how ketamine — a drug that blocks a brain receptor called the NMDA receptor — can lift depression symptoms quickly and for a sustained time in people and in animals. They describe possible ways ketamine works: it may boost another type…
This study used mouse brain cells grown in the lab and live mice to find how low doses of ketamine act quickly to reduce depression-like and anxiety-like behaviors. The researchers found that ketamine lowers activity of a molecule called calcineurin. That change leads to more of a specific kind of…
