Excessive use of smartphones and computers throughout the day can worsen the quality of sleep at night in teens, a new study has found. Researchers followed almost 10,000 teens, ages 16 to 19, in Norway and found that the longer teens spent using electronic devices throughout the day, the worse their quality of sleep.
Adolescents who reported using screens for more than four hours had a 49 per cent greater risk of taking longer than an hour to fall asleep. Those who used a computer, smartphone or mp3 player during the hour before bed were significantly more likely to take longer than an hour to fall asleep.
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"The current recommendation is not to have a TV in the bedroom. It seems, however, that there may be other electronic devices exerting the same negative influence on sleep, such as personal computers and mobile phones," researchers said in the journal BMJ Open.
"The results confirm recommendations for restricting media use in general," they said. Researchers in the study asked teenagers about their use of computers, smartphones, mp3 players, tablets, game consoles and televisions. They also asked them about their sleeping routines and how much sleep they needed to feel rested.
Using a screen for more than two hours after school was linked to both taking longer to fall asleep, and sleeping for less time, 'The Times' reported. While teens said they needed an average of eight or nine hours of sleep to feel rested, those who spent more than two hours emailing or chatting online were more than three times as likely to sleep for less than five hours.
Those who spent more than four hours in front of any screen were more than 3.5 times as likely to sleep for less than five hours. The researchers said screen time might simply replace sleeping time, or could interfere with sleep by stimulating the nervous system. The light emitted from the screens might also interfere with the body clock.