A new app was invented by the researchers from Northwestern University to detect your depression.

For the study, the research team recruited 40 adult participants through a Craigslist posting. The Purple Robot, a sensor data acquisition app was installed on participants phones, and data was tracked for two weeks using tools such as GPS, according to the study.

According to researchers, of the 40 participants only 28 produced usable data. Of those 28, 14 showed signs of mild to severe depression, while the other 14 revealed no symptoms.

Researchers found that the more time people spent using their phones, the more likely they were to show symptoms of depression. The 14 participants who showed signs of depression spent an average of 68 minutes a day using their phones, while those who weren’t depressed spent just 17 minutes on the phone.

The research could ultimately lead to monitoring people at risk of depression and enabling health care providers to intervene more quickly. The study was published in the Journal of Medical Internet Research.

By Lizitha