The way you use your smartphone may reveal if you are depressed, a new study suggests.
In the study, 28 people ages 19 to 58 downloaded an Android app to their smartphones. The app, called Purple Robot, collected information about users' location (using the phone's GPS) and how often they were using their phone, based on whether the screen was on or not.
The participants also completed a questionnaire intended to measure their symptoms of depression. About half of the participants had no symptoms of depression, while the other half had symptoms ranging from mild to severe.
The researchers found that by using only the data from the participants' phones, they could identify which participants had symptoms of depression with 87 percent accuracy.
The finding that behaviors related to depression can be detected by analyzing data from a phone "opens the possibility of a new generation of behavioral intervention technologies," which could offer support to people or reinforce behaviors that may improve depression, the researchers said.
The researchers also found that the people in the study who had symptoms of depression tended to spend more time at home, and visited fewer locations, than those without symptoms of depression. People with symptoms of depression also kept schedules that were less regular; for example, they might leave the house for work at a different time each day.
People with depression often experience a lack of motivation or energy to go out and do things, which could partly explain the findings, said study researcher David Mohr, director of the Center for Behavioral Intervention Technologies at Northwestern University Feinberg School of Medicine in Chicago. [10 Technologies That Will Transform Your Life]
The study also found that people with symptoms of depression also used their phones more — about 68 minutes a day on average, compared with just 17 minutes a day for people without symptoms of depression.
The app could not tell what people were doing on their phones, but they were likely surfing the Web or playing games, Mohr said. Such activities may offer a way to avoid thinking about painful feelings or difficult relationships, Mohr said.
"This can improve the identification of depression and the ability of healthcare settings to allocate resources to those in need," the researchers wrote in their study.
The researchers noted that the new study is small and more research is needed to confirm the findings.
The study is published today (July 15) in the Journal of Medical Internet Research.