We use them for everything. From tracking flights to tracking footsteps, for recreation, education, work and, sometimes, even phone calls, that little screen in your pocket has become the ubiquitous, omniscient companion for the 21^st century. Concern over the ubiquity of smart phones has been publicized heavily over the years, with many researchers noting a relationship between smartphone use and such conditions as ADHD, technology addiction, insomnia and depression. Yet, a team at Northwestern University has concluded that the smartphone may be a vital ally in accurately diagnosing depression.

Their study, which gathered data over two weeks using built-in global positioning systems (GPS) and a usage sensor app, found that depressed individuals used their smartphones at rates four times that of non-depressed individuals, with an increase from roughly 17 minutes per day to 68.

Researchers also found that, with the right data, smartphones actually act as a bellwether for identifying many key warning signs of depression. Information on the frequency and duration of smartphone usage, circadian movement or sleep-wake schedules, and the variance of subjects’ movements and location all reflect depressive symptoms, including changes to sleep patterns and appetite, loss of interest and lack of concentration, with 86.5% accuracy.

According to Sohrob Saeb, the study’s lead author, smartphones particularly outstripped the accuracy of daily questionnaires, which are often subject to patients’ biases or unreliability in self-reporting.

“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 senior author David Mohr, director of the Center for Behavioral Intervention Technologies at Northwestern University Feinberg School of Medicine. “We now have an objective measure of behavior related to depression. And we’re detecting it passively. Phones can provide data unobtrusively and with no effort on the part of the user.”

Find out more information about this study http://www.northwestern.edu/newscenter/stories/2015/07/your-phone-knows-if-youre-depressed.html

For more information on depression, its symptoms and treatment options, visit the National Alliance on Mental Health website. https://www.nami.org/Learn-More/Mental-Health-Conditions/Depression