Increased screen time found to raise depression risk in teen girls: Study

A study published in 'PLOS Global Public Health' tracked 4,810 Swedish students aged 12-16 for a year, collecting data on screen time, sleep patterns, and depressive symptoms

Excessive screen time can affect one's sleep, thereby increasing risk of depressive symptoms -- especially among teenage girls, according to a new study.

Studies have consistently linked use of screens and devices with a poorer quality of sleep and a higher chance of mental health conditions, such as anxiety and depression.

However, researchers from Sweden's Karolinska Institute said that sleep problems and depression can often coincide, and the direction of these links has been unclear.

For the study, findings of which are published in the journal 'PLOS Global Public Health', the team tracked 4,810 Swedish students aged 12-16, collecting data on sleep quality and quantity, depressive symptoms, and screen usage over the course of a year.

An increased screen time led to deteriorated sleep within three months, impacting both the duration and quality of sleep, the study found.

Screen time was also found to postpone sleep times towards later hours -- disrupting multiple aspects of the human sleep-wake cycle at once.

Further, the researchers found that among boys, screen time directly increased their risk of depression after twelve months, while among girls the depressive effect was caused through sleep disturbances.

Sleep was found to explain about 38 per cent to 57 per cent of the link between screen time and depression in girls.

Boys who spent more time on screens also experienced sleep disruptions, but these were not strongly associated to later depression, the researchers said.

The study showed that "screen-sleep displacements impact several aspects of sleep simultaneously. Displacements led to elevated depressive symptoms among girls but not boys," the authors wrote.

"Boys may be more prone to externalising symptoms due to sleep loss," they wrote.

In September 2024, the Swedish Public Health Agency announced guidelines that teenagers should not use no more than two-to-three hours of daily leisure screen time, partly to promote better sleep.

The study's results could "mirror potentially beneficial public health effects of national screen time recommendations," the authors said.