Studies have linked excessive screen time to mental health problems like depression in adolescents. New research now suggests that this link may be driven by shorter sleep and worse organization of brain white matter. The corresponding study was published in JAMA Pediatrics.
“Our study considered digital screen time as a broad definition but it’s really important to look at the nuances. Time of day when you are using your smartphone and what content you engage with matters,” said lead author of the study, Dr. João Paulo Lima Santos, M.D., research instructor in psychiatry at the University of Pittsburgh, in a press release.
For the study, researchers analyzed data from 976 participants, including 460 children and their parents/ caregivers. Data included results from questionnaires assessing screen time, sleep duration, and depressive symptoms as well as brain imaging of white matter tracts involved in depression: the cingulum bundle, forceps minor, and uncinate fasciculus.
Ultimately, the researchers found that more daily screen time at age 9- 10 years was linked to more depressive symptoms at age 11-13. Their analyses further revealed that shorter sleep duration and worse cingulum bundle organization at age 11-13 may explain over 36% of the association between more screen time and more depressive symptoms.
“Brain white matter connections are just like highways that connect cities. If these highways are not well-maintained, traveling from one city to another can be slow and inefficient, or even disrupted,” said Lima Santos.
The findings emphasize the importance of promoting healthy habits and balancing screen time with adequate sleep, wrote the researchers in their study. In future research, Lima Santos hopes to collect screen use data directly from phones to learn more about whether the specific time of day when teens use their screens matters. He suspects that the hour before sleep may have an impact, however more research is needed.
Sources: JAMA Pediatrics, EurekAlert