Your smartphone thinks you're sad

Imagine a smartphone software application that monitors your state of mind. The device could help you, your family and perhaps your employer identify when you're going through a rough stretch and dealing with depression or stress.

Would you use such a tool, or allow information it gathers to be accessed by others? Researchers at Dartmouth College think the answer is yes. They built an Android app that aims to track a person's mental health. StudentLife, as the software is called, "compares students' happiness, stress, depression and loneliness to their academic performance, (and) also may be used in the general population -- for example, to monitor mental health, trigger intervention and improve productivity in workplace employees," according to a news release.

Dartmouth computer science professor Andrew Campbell, the study's senior author, said the app came about as a way for he and his colleagues to measure the stresses and pressures his students were dealing with.

"Unless they came to see me in office hours, I remained clueless to help them if they were stressed-out or struggling," he said. "The app reveals for the first time their levels of stress, or 'flourishing' (a word that means how positive or good they feel), depression and loneliness -- all factors that students run up against, particularly at very demanding academic environments such as Dartmouth."

The app, which was tested by 48 Dartmouth students over a 10-week period, uses passive data from sensors embedded in a smartphone, including the device's microphone, accelerometer, light sensor and location detectors. The sensors automatically collect information on a variety of factors, such as the amount of time users slept, the number of conversations they engaged in and other social activities. That data is then run against clinical surveys on mental health to determine the smartphone owner's state of mind.

Campbell says that having a smartphone app that can monitor your level of happiness or depression could have widespread, practical applications, such as making a call for assistance if a smartphone detects its owner might be struggling emotionally.

"The idea is that we build effective interventions," he said. "A simple one could be my phone knows I'm struggling and books me in for an appointment to see a clinician. Or, the vision I hope will unfold, that the phone not only measures your mental state 24/7, but if it detects the trigger of decline... provides tailored intervention to you -- advice that it knows you are open to acting on."

Campbell notes there are already some startup companies using smartphone technologies to assist people with chronic conditions, such as diabetes, in keeping track of their health, while sharing that information with their healthcare providers. He also expects that, within five years or so, the app he and his colleagues have been working could be a marketable and mainstreamed product.

The big challenge is ensuring that any data collected by the app remains confidential. "I think the solution to the privacy problem is to allow the user to control their data and allow access to it if they choose," Campbell said.

And given that people already use apps to measure their heart rates during exercise, keep track of calories consumed, miles run and other personal health data, it may not be such a stretch to imagine that they would use technology to assess their psychological fitness.

"I think the sensors on phones and wearables are going to be the source of a huge amount of personal data that individuals and companies will attempt to monetize, hopefully with the right privacy safeguards in place," Campbell said. "But as we've learned about technology, it moves on no matter what safeguards are in place."