Teen suicides have been growing more common, and no one really knows why — or how to stop it.

Here are some sobering statistics. Between 2009 and 2017, the number of high schoolers who contemplated suicide reportedly increased by 25 percent. Deaths by suicide among teens increased by 33 percent in that time period as well. Suicide is now the second leading cause of death among teens after accidents (traffic, poisoning, drownings, etc). But don’t be mistaken: Teen suicide is still rare. Just 10 out of 100,000 teens ages 15 through 19 die this way. But even a single death is one too many.

Researchers have been working for decades on interventions to decrease the rate of suicides among teens (as well as among adults). It’s hard. For one, many people who died by suicide never got mental health treatment at all. And the ones that did, well, there’s very limited evidence on what works.

In fact, according to the authors of a new paper in JAMA Psychiatry I read recently, “To our knowledge, no other intervention for suicidal adolescents has been associated with reduced mortality.” That line stopped me cold. There’s nothing that’s been scientifically proven to save lives when it comes to suicidal teens, except what they discovered in this paper?

I called up Cheryl King, who’s been studying youth suicide prevention for the past 30 years at the University of Michigan and was the lead author on the new JAMA Psychiatry paper.

King explained that the paper revisits a clinical trial she and colleagues conducted more than a decade ago. In the trial, half of 448 teens who were admitted to a psychiatric hospital for suicidality were asked to select up to four adults in their lives to receive continuing education and suicide prevention. Simply put: The adults were getting education and support, so they could better support the teen.

Read the full article at Vox.