A study published in the journal JAMA Pediatrics found that the teens who spend too much time on social media or watching television become notably more depressed.
The six-year study tracked over 3,800 students in Montreal, asking them to track (in class) both how much time per day they had spend watching TV, browsing social media and playing video games. As part of the same survey, they were asked to measure their level of depressive symptoms, such as loneliness and sadness.
An increase of as little as one hour of social media interaction from normal levels would result in a measurable increase in depression, the study found. (Researchers found no correlation, it's worth noting, between signs of depression and video games.)