Rising suicide rates and depression in US teens and young adults have prompted researchers to ask a provocative question: Could the same devices be used to help to tech-age angst?  The idea has sparked a race to develop apps that warn of impending mental health crises. Call it smartphone psychiatry or child psychology 2.0.

Studies have linked heavy smartphone use with worsening teen mental health. But as teens scroll through Instagram and Snapchat, YouTube videos, they also leave digital footprints that might offer clues to their psychological well-being.

Changes in typing speed, voice tone, word choice and how often kids stay home could signal trouble, according to preliminary studiesThere might be as many as 1,000 smartphone "biomarkers" for depression, said Dr. Thomas Insel, former head of the National Institute of Mental Health and now a leader in the smartphone psychiatry movement.

Researchers are testing experimental apps that use artificial intelligence to try to predict depression episodes or potential self-harm. "We are tracking the equivalent of a heartbeat for the human brain," said Dr. Alex Leow, an app developer and associate professor of psychiatry and bioengineering at the University of Illinois' Chicago campus.

At least, that's the goal. There are technical and ethical kinks to work out-including privacy issues and making sure kids grant permission to be monitored so closely. Developers say proven, commercially available mood-detecting apps are likely years-but not years-away.

Using smartphones as mental illness detectors would require informed consent from users to install an app, "and they could withdraw permission at any time," said Allen, one of the creators of an app that is being tested on young people who have attempted suicide.

"The biggest hurdle at the moment," Allen said, "is to learn about what's the signal and what's the noise-what is in this enormous amount of data that people accumulate on their phones that is indicative of a mental health crisis."

Smartphone app 

Suicide has risen to the second leading cause of death for ages 10 to 34. Rates between teen girls doubled from 2007 to 2015, climbing to 5 per 100,000. And among boys, rates jumped 30 percent, to 14 in 100,000. A recent study suggested to parallel rise in smartphone use likely contributed.

If smartphones prove to be accurate mood predictors, developers say the ultimate goal would be to use them to offer real-time help, perhaps with automated text messages and links to help lines, or digital alerts to parents, doctors or first responders.

Facebook is already doing just that with what it calls "proactive detection." Last year, after a live-streamed suicide, Facebook trained its AI systems to flag certain words or phrases in online posts that could indicate imminent self-harm. Friends' comments expressing concern about the user's well-being are part of the equation.

The ongoing research includes: – A Stanford University study involving about 200 teens, including kids at risk for depression because of bullying, family circumstances or other life stresses. As part of the research, teens who have been tracked since grade school get an experimental phone app that surveys them three times daily for two weeks with questions about their mood.

At the University of Illinois' Chicago campus, researchers studying depression and mania in bipolar disorder are using crowdsourcing to test their experimental phone app. Anyone can download the free app, and nearly 2,000 have so far, agreeing to let the users continuously track things as typing speed, number of keystrokes and use of spellcheck. Participants include healthy people, and their data will help Zero in on changes in phone use that signal onset of mood problems, said Leow, the psychiatry and bioengineering expert who helped develop it.

"Digital phenotyping" app

The study is for ages 18 and up, but if it came to work, the technology could be used in kids too, Leow said. Mindstrong, to Palo Alto, California, tech health company co-founded by Insel, the former NIH official, is testing to "digital phenotyping" app in several studies. Insel thinks the technology has promise to transform psychiatry, but that the most important question is whether it can be used to improve patient health.

Verily, a tech health arm of Google parent company Alphabet, is developing a similar app but declined to elaborate beyond statement from its mental health leader, Menachem Fromer. I have cited two key goals: making predictions about someone's mental health and their symptoms and "discovering new subtypes of disease that may inform treatment decisions."