One of the problems with depression is that because it often forms so gradually, many people don’t even realize that they’re suffering from it – they just assume that normal life is pretty dreary. With that in mind, researchers from Chicago’s Northwestern University have devised a method of analyzing at-risk individuals’ smartphone use, to see if they’re developing signs of the disorder.
In a study conducted at the university, the phone-usage of 28 test subjects (20 women and eight men, average age of 29) was monitored over a two-week period. They also all completed a PHQ-9 questionnaire, which is commonly used to assess depression by asking questions about symptoms such as sadness, hopelessness and sleep disturbances.
When the smartphone-activity and PHQ-9 data was tabulated and cross-referenced, it was found that the 14 subjects who scored highest for depression on the questionnaire also had some phone-related traits in common. These included more overall use of their smartphones (an average of 68 minutes a day, as opposed to 17 for the other test subjects), spending more time at home or in fewer locations (as measured by their phone’s GPS tracking feature), and a less regular day-to-day travel schedule.
While increased phone usage might suggest more contact with other people, the researchers believe that it instead indicates non-social activity such as web-surfing and game-playing. These could be examples of “avoidance behavior,” that people engage in to avoid dealing with mental anguish.
The fact that the subjects left home less often is in keeping with the known fact that depressed people tend to lack the motivation to get out and do things, instead opting to remain sedentary. Likewise, not maintaining a consistent daily schedule has also been linked to depression.
All told, the study matched smartphone use to subjects’ level of depression with 87 percent accuracy. While approaches such as questionnaires are certainly helpful, the researchers believe that patients often lack accuracy when performing such self-assessment techniques.
“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,” says Northwestern’s Dr. David Mohr, senior author of a paper on the study. “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.”