What smartphones can tell us about depression -- and how they can help in treating it

CHICAGO, Ill. (WGN) -- They hold all the information we need to navigate our daily lives. Smart phones give us weather and news updates, store our photos, music and phone numbers. And now our life line to the outside world can tell us what we're feeling on the inside.

They go everywhere with us, so it's no surprise researchers at Northwestern Medicine utilized the mobile device to help them collect valuable information ... no questions asked.

David Mohr, PhD, Northwestern Medicine, preventive medicine professor: "People get very tired very quickly from entering data about themselves. So we began to realize with mobile phones there is a growing complement of sensors in there that can detect things of interest."

So Professor David Mohr and his team developed purple robot – an app designed to passively collect data useful to mental health researchers. They loaded the software onto the phones of 28 random study participants.

Dr David Mohr: "We started this study really looking at two variables. One is GPS, so location, how people move through geographic space and then how much they are on their phones and how that might relate to depression."

Both – it turns out – are key factors in measuring mood and symptoms of depression. The app helped the researchers identify participants with depressive symptoms with 87 percent accuracy.

Dr David Mohr: "What we found was the number of places people go is significantly related to depression. So the more places people go on average in a day, the less likely they are to be depressed. You can imagine for somebody who is depressed, who is staying home and not going out much, you can see how that data is representative of someone being depressed. Movement is important."

And so is the amount of time we spend using our phones. The average daily usage for depressed individuals was 68 minutes compared to just 17 minutes for those not suffering with depression.

Dr David Mohr: "The more time somebody spends on the phone, not necessarily calling people or texting but surfing the web, looking at apps, the more time people spend the more likely they are to be depressed, and we think part of that is related to the avoidance we see in depression. People look for distractions partly because of their mood, partly because they don't want to deal with other things that might make them feel uncomfortable."

Dr Mohr hopes the ongoing research helps care providers monitor patients more closely and intervene more quickly.

Dr David Mohr: "Only 30 percent of people in the US in any given year who have depression get treated for it. Once we're able to detect this with a reasonable degree of accuracy, we can use this to monitor at risk populations and allow care providers to reach out when there's likelihood they're depressed, to check in, get people on medications or into treatment more quickly."

In addition to studies that use mobile phone sensor data to better understand depression, Northwestern Medicine researchers are also running a number of trials to treat depression and anxiety using evidence-based interventions.