Too much screen time affects sleep in teenagers, which may be a major reason for rising rates of depression, especially among girls. A study tracking more than 4,800 teenagers found that screen use affects sleep quality and sleep duration, which in turn predicts depressive symptoms.

For girls, sleep deprivation was the main link between screens and emotional distress, while boys were more directly affected. Researchers say reducing screen time could reduce the mental health burden on young people.

Too much screen time can disrupt sleep in teens, while not getting enough sleep may increase the risk of depression, especially in girls. This is the finding of a new study published in PLOS Global Public Health by Sebastian Hockby and colleagues at Karolinska Institutet in Sweden.

The Swedish Public Health Agency recently recommended that teenagers limit recreational screen time to two to three hours a day, in part to promote healthier sleep. Previous research has linked prolonged screen use to poor sleep and mental health problems in teenagers, but the exact relationship between these factors is unclear, especially because sleep problems and depression often occur together.

In the new study, researchers followed 4,810 Swedish students aged 12 to 16. They collected data on screen habits, sleep patterns and depression symptoms at three points over a year.

Researchers found that increased screen time led to a decrease in sleep quality over three months, affecting sleep duration and quality. Screen time can also cause sleep to be pushed later, disrupting multiple aspects of the human sleep-wake cycle simultaneously.

In boys, screen time had a direct negative effect on depression 12 months later, whereas in girls, the effect on depression was mediated through sleep disturbance. Sleep explained about half (38%-57%) of the association between screen time and depression in girls. Boys who spent more time with screens also experienced disrupted sleep, but this was not strongly associated with later depression.

The authors concluded: "In this study, we found that adolescents with higher screen time also develop poorer sleep habits over time. This, in turn, leads to increased levels of depression, especially among girls. Our findings do suggest that reducing screen time appears to be healthier, which is consistent with previous statements from the World Health Organization... If screen time can be reduced in some way, for example through public health policy, our findings suggest that the burden of depressive states may be reduced among young women and even young men in Sweden."

Compiled from /ScitechDaily