Your Phone Knows When You’re Depressed: New App Can Identify Behaviours Linked to Depression

Your phone can recognize the warning signs of depression even if your friends and family can’t.

A study released yesterday in the Journal of Medical Internet Research revealed that mobile phones may be able to identify whether an individual could be suffering from depression.

According to the report, healthcare professionals frequently fail to identify the symptoms of depression, delaying treatment for months or years. So, researchers turned to an app to do just that, allowing for an objective measure of behaviour related to depression.


Unlike a series of grueling questions by medical professionals, phones can provide data unobtrusively and with no effort on the part of the user. Our cell phones have become ever-present fixtures in our lives, and can perpetually measure a person’s activity, location, and environment, according to researchers at Northwestern University.

They attached a mobile app called “Purple Robot” to the phones of 28 participants for two weeks. Upon collecting their GPS and phone usage data, they found that half of the participants suffered from mild to severe depression and the other 14 had no signs of depressive symptoms.

So, what are the behaviours that may indicate depression in the first place? According to the researchers, warning signs include spending more time at home, using your phone at higher than average rates, and having an erratic schedule.

The app’s GPS data determined whether the participant was in a stationary state or in a transition state, and where the users spent most of their time. The researchers were also able to determine to what extent a person’s movements followed a 24-hour or circadian rhythm. Meaning, if a person’s routine involves them leaving and returning to work around the same time every day, they have a high level of circadian movement.

On the other hand, someone with an erratic schedule experiences low levels of circadian movement – and these are highly correlated with depression, according to the study.

The app is also able to detect travel time, total distance moved, and both phone use frequency and duration. Apparently, time spent on the phone was longer for those who experience depression. The report also found that people who experienced mild to severe symptoms of depression tended to move around less and have a less regular schedule.

The report said the findings were consistent with the patterns of loss of motivation, decreased activity, and social withdrawal that characterize depression.

“People are likely, when on their phones, to avoid thinking about things that are troubling, painful feelings, or difficult relationships – it’s an avoidance behaviour we see in depression,” said senior author David Mohr, director of the Center for Behavioral Intervention Technologies at Northwestern University Feinberg School of Medicine, in a press release.

“The significance of this is we can detect if a person has depressive symptoms and the severity of those symptoms without asking them any questions,”said Mohr.

By scoring individuals on circadian movement, location variance, home stay, phone-use duration, and phone-use frequency, researchers say they were able to estimate depression on unseen participants with 87 per cent accuracy.

The report did caution that the study was based in a small sample group and that the results needed to be replicated in a larger study to be confirmed. Either way, it’s a step in the ever-growing effort to identify signs of mental illness and depression.

After all, mental illness affects one in five Canadians at some point in their lives.