Technology 24 July 2015 Your phone can tell when you’re depressed Where you take your phone, and how much you use it, can give doctors an insight into your mental health. Does your phone know you best? Photo: Getty. Sign UpGet the New Statesman's Morning Call email. Sign-up Who knows you best? Your friends? Family? Partner? Yourself? While all the above may all have insight into your deepest thoughts and feelings, there's a non-human who could trump them all when it comes to knowing your daily habits: your phone. In fact, a recent study has suggested that phone data could be the best way to pick up on signs of depression, based on where you go and how much you use it. The research comes from Northwestern University's Centre of Behavioural Intervention Technologies, which sent out 28 participants with usage and location trackers on their phones, plus an app which asked regular questions about their mood. Before the study started, those involved also filled out a survey through which they could self-report depressive symptoms. The study's conclusion? The phones managed to pick up symptoms and behaviours associated with depression among the participants, sometimes even better than the participants identified them themselves. Warning signs for depression included an irregular routine, not leaving the house much, plus using your phone a lot (this one unsettled me a bit). The average smartphone can easily pick up on all three using software which measures phone software, plus basic GPS. Of course, the sample size was very small, and the study's conclusion also notes that researchers need to replicate it on a much larger sample, using patients showing clinical symptoms of depression to check the method's effectiveness. But the (even very preliminary) findings make sense: healthcare is in dire need of better data on patients, and objective information about your daily activity can be a lot more informative than self-reported information. The researchers also suggested that tracking patients like this could allow the medical profession to reach out to anyone who starts showing warning signs of depression, and intervene before things got worse. This would need to be handled carefully - there are all kinds of issues around data protection and privacy - but it could allow at-risk populations to be monitored far more effectively. The idea reminded me of Samaritans Radar, an app launched last year by the charity which alerts users if those they follow on Twitter use phrases like “tired of being alone”, “hate myself”, “depressed”, “help me”, or “need someone to talk to”. Samaritans later pulled the app after criticism over... yep, you guessed it, privacy converns. Maybe the public would be less suspicious of an app that only fed data to doctors and therapists, but it seems like we're still not very comfortable with others tracking our locations and state of mind, even if it's for our own good. › What actually happens at a CLP nomination meeting, anyway? Barbara Speed is comment editor at the i, and was technology and digital culture writer at the New Statesman, and a staff writer at CityMetric. Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!