Spending longer hours on TV, iPad leads to sleep problems in teens

If you are teenager and love to watch TV or use tablets for longer hours, you might want to reconsider, as a new study suggests that longer screen time throughout the day before going to bed, leads to sleep problems in teens.

The findings are based on almost 10,000 16 to 19 year olds, all of whom were part of the Norwegian youth@hordaland study in 2012. The teens were asked how much screen time they spent outside of school hours, and on what activities, for any of the following electronic devices: computer; smartphone; Mp3 player; tablet; games console; and TV.

They were also asked questions about their sleep routine on weekdays and at weekends: when they normally went to bed and got up; how much sleep they needed to feel rested; and how long it took them get to sleep (sleep onset latency).

While games console use was more popular among the boys, girls were more likely to use smartphones and Mp3 players. Almost all of the teens said they used one or more electronic devices shortly (an hour) before going to bed.

Although frequency of use differed among the various devices, use of any device during the day and in the hour before bedtime was linked to a heightened risk of taking longer than 60 minutes to get to sleep.

In particular, use of a computer, smartphone, or Mp3 player in the hour before bedtime was significantly associated with taking longer to fall asleep. A period of more than half an hour is normally defined as long sleep latency in adults, say the researchers.otal daytime screen use of more than 4 hours was linked to a 49 percent greater risk of taking longer than 60 minutes to fall asleep.

And a total of more than 2 hours of screen time after school was strongly linked to both longer sleep onset latency and shorter sleep duration.

When the analysis looked at individual devices, the strongest association for shortened sleep and less sleep than deemed necessary was found for computers, although this technology was one of the most commonly used of all the electronic platforms.

Screen use may simply replace sleeping time or may interfere with sleep by stimulating the nervous system, suggest the researchers, in a bid to explain their findings. lternatively, the light emitted from electronic devices may interfere with the body clock (circadian rhythm).

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 PCs and mobile phones. The results confirm recommendations for restricting media use in general, the researchers concluded.

The study is published in the online journal BMJ Open.