Teen girls who spend more time on their phones are more likely to have trouble sleeping and show signs of depression, according to a new study from Sweden.
Researchers from the Karolinska Institute followed 4,810 students between the ages of 12 and 16 for a year. They looked at how long teens used their devices each day, their sleep habits, and their mental health.
Both girls and boys in the study used screens for three to four hours daily—longer than the two to three hours recommended by Sweden’s public health agency. But the impact of screen time was worse for girls.
Girls in the study had depression scores twice as high as boys, even though their screen time was similar. They also experienced more “sleep displacement”—going to bed later than their body’s natural schedule would prefer. This led to shorter, lower-quality sleep and disturbed their body’s normal sleep patterns.
“Less screen time seems healthier,” the researchers said, suggesting that cutting down could help reduce depression in young people—especially girls.
The findings were published in the journal PLOS Global Public Health and support past research. One earlier study of 45,000 Norwegian university students also linked screen use at bedtime with insomnia and shorter sleep.
Still, experts say more research is needed. This study only shows a link—not a cause—between screen use and mental health issues. Also, teens reported their own screen use, which can be unreliable.
Some scientists, like Professor Chris Ferguson of Stetson University in the U.S., warned not to jump to conclusions. But others say the study shows why clear rules on screen use—especially on school nights—could help.
Professor Ben Carter from King’s College London said that national guidelines might “empower parents” and help teens get better sleep. “Sleep is essential in teen development,” he noted.
While the study isn’t proof that phones cause depression, it adds to growing concern about how screen time may affect young people’s health—especially teenage girls.
Read more:
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- Smartphone Overuse Linked To Lower Happiness In Kids & Teens
