A dose of ketamine can be far more effective than a traditional sedative at easing suicidal thoughts, according to new research. This finding could open up the way for new treatments for people suffering with severe depression.

Previous studies have shown that the anaesthetic drug can be an effective antidepressant, but this research looked at suicidal thoughts in particular, and positive effects were noted within the first 24 hours.

While it's too early to call ketamine a perfect and universal solution for treating suicidal tendencies, it does offer a promising alternative for people who aren't seeing any improvement from existing medication, according to the team from the Columbia University Medical Center in New York.

"This study shows that ketamine offers promise as a rapidly acting treatment for reducing suicidal thoughts in patients with depression," says the lead researcher, psychiatrist Michael Grunebaum.

"Additional research to evaluate ketamine's antidepressant and anti-suicidal effects may pave the way for the development of new antidepressant medications that are faster acting and have the potential to help individuals who do not respond to currently available treatments."

First developed as a fast-acting anaesthetic in the 1960s, and used to treat soldiers on the battlefield, ketamine has since also become known as an illicit party drug – it can bring on feelings of euphoria and vivid hallucinations, alongside some nasty side effects that in extreme cases can result in a coma or even death.

More recently doctors have started exploring how the drug could treat depression when taken in low doses. One study from last year found it caused mood improvements in three-quarters of patients.

For the new research, a low dose of ketamine was put up against the sedative midazolam in a group of 80 volunteers actively considering suicide. After 24 hours, the ketamine was found to be significantly more effective at controlling those thoughts.

Factoring in ketamine's general antidepressant qualities with the help of previous studies, researchers say around one-third of the effect was specifically targeting these suicidal thoughts, making it potentially very useful for future treatments on this particular issue.

Even better, the positive effects of ketamine on suicidal thoughts were still being shown six weeks after the initial dosage, albeit with the help of a standard course of psychiatric treatment at the same time.

All of which means ketamine ticks a lot of useful boxes: it works fast, it lasts for a significant time, and it can be relatively safe, if administered properly.

"There is a critical window in which depressed patients who are suicidal need rapid relief to prevent self-harm," says Grunebaum. "Currently available antidepressants can be effective in reducing suicidal thoughts in patients with depression, but they can take weeks to have an effect."

"Suicidal, depressed patients need treatments that are rapidly effective in reducing suicidal thoughts when they are at highest risk. Currently, there is no such treatment for rapid relief of suicidal thoughts in depressed patients."

So can doctors start prescribing ketamine to anyone feeling suicidal? Not quite yet. First the side effects – which in this study were noted to be an increase in blood pressure and a feeling of being spaced out – need to be carefully monitored, and over a longer term.

Secondly, taken on its own, without any extra treatment, the antidepressant effects of ketamine are thought to last around a week, which makes regular treatment via needle or catheter something of a challenge.

Thirdly, the use of ketamine as an antidepressant has yet to be officially greenlit by the authorities, though one such drug is waiting for approval from the Food and Drug Administration (FDA) in the US. 

Nevertheless, ketamine could prove very helpful indeed in cases where people aren't responding to current treatments, as long as we can get a better understanding of its impact and effect on the brain.

And with suicide rates in the US sharply increasing by 26.5 percent between 1999 and 2015, this is a problem that needs addressing sooner rather than later.

"I wouldn't call it the breakthrough [of depression and suicide treatment], rather just a breakthrough," Grunebaum told Ed Cara at Gizmodo.

"What's the most breakthrough aspect of ketamine is that it seems to have a different mechanism of treating depression than currently approved medications."

The research has been published in the American Journal of Psychiatry.