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An anesthetic that is also used as a ‘club drug’ can help people with dangerously suicidal thoughts, rapidly treating their depression and wish to die, researchers reported Monday.

The drug, called ketamine, has already been shown to help when given intravenously. Developers tried a nasal spray formulation that they thought might act more quickly and be easier to give.

The hope is to help patients hold on until more traditional antidepressants and therapy have a chance to cikc in, developers said.

The nasal spray showed benefits after four hours, the team at Janssen Research and Development reported in The American Journal of Psychiatry.

But the researchers are also aware that the drug can be abused and are coming up with ways to prevent that.

The team tested 68 patients who showed up in emergency rooms with severe depression and thoughts of suicide.

“They had to be at imminent risk. Not only were they thinking about suicide they were thinking about acting on those thoughts,” Dr. Carla Canuso, a psychiatrist at Janssen parent company Johnson & Johnson, told NBC News.

“Sixty percent of the patients in the study had made an attempt. These were high-risk patients,” she added.

“Half of participants required suicide precautions in addition to hospitalization,” the team wrote.

All the patients got comprehensive care, including counseling and antidepressants. Half also got the nasal spray, called esketamine, and half got a saline placebo.

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Within four hours, 34 percent of the patients given esketamine lost their immediate thoughts of suicide, saying they ‘enjoy life or take it as it comes’, compared to 23 percent who got placebo, Canuso’s team found.

At the same time, 55 percent of those on who got a placebo still said they were “probably better off dead”, compared to 26 percent who got esketamine.

The patients got esketamine spray or placebo twice a week for four weeks, plus standard treatment.

After 25 days, 77 percent of the patients given esketamine said they ‘enjoy life or take it as it comes’, compared to 58 percent of those who got placebo, the researchers said.

The four weeks of treatment was deliberate, Canuso said.

“That is the period of time it normally takes a standard antidepressant to kick in,” she said.

The effects wear off over time. “The failure to demonstrate longer-term benefits raises questions about the risk versus the benefit of long-term use,” noted Dr. Robert Freedman, who edits the American Journal of Psychiatry.

And there were side-effects, include a bad taste in the mouth, nausea and an unpleasant feeling of dissociation.

“The goal of treatment would be to have treatment that works rapidly but also bridges the gap to the time that a standard antidepressant works,” Canuso said.

“There is no approved treatment for patients in suicidal crisis right now. What we normally do with these patients is put them on standard antidepressants and hospitalize them.”

Depression is very common. About 8 percent of kids age 12 and older and adults have depression, according to the Centers for Disease Control and Prevention.

The CDC has sounded regular warnings about suicide rates in the U.S. It’s the 10th leading cause of death overall. In 2015, 44,000 people in the United States died by suicide and more than a million tried it.

Ketamine is a promising drug for treating acute, severe depression but it’s also got a high potential for abuse, Freedman said.

“The abuse of oxycodone, with generalization to both fentanyl and heroin, has led to a national epidemic of opioid-caused deaths,” Freedman and colleagues wrote in an editorial.

“Diversion of ketamine intended for pediatric and veterinary anesthesia, its current approved use, is occurring already," they added. "As physicians, we are responsible for preventing new drug epidemics.”

Janssen spokesman Greg Panico said the company is already working on this problem.

“The drug will not be distributed in pharmacies or given to patients to take home,” he said.

“It will be distributed through a special process.” Esketamine is not yet approved for use to treat suicide. The company is still testing it and must then seek approval from the Food and Drug Administration.

But if it does win approval, it will be packaged as a single-dose spray, Canuso said.

“Esketamine nasal spray will be delivered through a metered, single-use, disposable nasal spray device,” she said.

Warning signs for suicide include: