Cell phones and screens keep your child awake

Highlights of the story

Devices in the bedroom are associated with children losing sleep time and quality, new research says

Even kids and teens who don’t stay up late online sleep poorly


Today, teachers are often faced with classrooms full of gaping students who stayed up late taking selfies or playing online games.

For children and teenagers, using cell phones, tablets and computers at night is associated with loss of sleep time and sleep quality, new research finds. Even kids who don’t use their phones or other technologies in their bedrooms at night lose their eyesight and become prone to daytime sleepiness, the analysis published today in JAMA Pediatrics finds.

The analysis found “a consistent effect pattern across a wide range of countries and environments,” said Dr. Ben Carter, lead author and senior lecturer in biostatistics at King’s College London.

Carter and colleagues searched the medical literature to identify hundreds of applicable studies conducted between Jan. 1, 2011, and June 15, 2015. They chose 20 research reports involving a total of 125,198 children, evenly distributed by gender, with a mean age of 14½ years. After extracting relevant data, Carter and his co-authors performed their own meta-analysis.

Few parents will be surprised by the results: The team found a “strong and consistent association” between media device use before bedtime and inadequate amount of sleep, poor sleep quality and excessive daytime sleepiness.

Surprisingly, however, Carter and his team found that children who did not use their devices in their bedroom still had their sleep interrupted and were likely to experience the same problems. The lights and sounds emitted by the technology, as well as the content itself, can be too stimulating.

While Carter admits that a weakness of the analysis was “the way the data was collected in the primary studies: self-reported by parents and children,” many of us will probably recognize the habits of our own families reflected in the statistics.

A large-scale poll in the United States by the National Sleep Foundation (PDF) reported in 2013 that 72% of all children and 89% of teenagers have at least one device in their sleeping environment. Most of this technology is used near bedtime, that same report found.

According to Carter and his co-authors, this ubiquitous technology negatively impacts children’s sleep by slowing down their sleep time when they finish watching a movie or playing another game.

Light emitted by these devices may also affect circadian rhythm, the biological processes of the internal clock, including body temperature and hormone release, the researchers explain. One specific hormone, melatonin, causes fatigue and contributes to the timing of our sleep-wake cycles. Electronic lights can slow down the release of melatonin, disrupting this cycle and making it more difficult to fall asleep.

Carter and his co-authors also suggest that online content can be psychologically stimulating, keeping children and teenagers awake well past the hour when they turn off their devices and try to sleep.

“Sleep is vital for children,” said Dr. Sujay Kansagra, director of the pediatric neurology sleep medicine program at Duke University Medical Center, who was not involved in the new analysis. “We know that sleep plays a critical role in brain development, memory, self-regulation, attention, immune function, cardiovascular health and much more.”

Kansagra, author of “My child does not want to sleep” noted that the period of greatest brain development is in our first three years of life, which corresponds to when we need and get the most sleep. “It’s hard to believe that this would be a coincidence.”

Kansagra said it’s possible that parents underreported children using devices at night, but more likely the technology is simply interfering with sleep hygiene. “Children who are allowed to keep devices in their room, for example, are more likely to avoid a proper sleep routine, which we know is helpful for sleep,” he said.

Dr. Neil Kline, a representative of the American Sleep Association, agrees that sleep plays an integral role in a child’s healthy development, even though we don’t know all the science behind it. There is even some research showing a link between ADHD and some sleep disorders.”

In many ways, the new study’s findings come as no surprise. “Sleep hygiene is significantly impacted by technology, especially in the teen years,” says Kline, basing his opinion not only on research but also on his own “personal experience as well as the anecdotes of many other sleep experts.”

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  • Sleep hygiene – tips that help to get a good, continuous and sufficient sleep – include a room that is quiet. “And that would mean removing items that interfere with sleep, including electronics, TV, and even pets if they interfere with sleep,” Kline said.

    Another important tip comes from the National Sleep Foundation, which recommends at least 30 minutes of “gadget-free transition time” before bed. Switch off for a better night’s sleep.

    Other recommendations for good sleep hygiene include not exercising (physically or mentally) too close to bedtime; establishing a regular sleep schedule; limit exposure to light before bedtime; avoiding stimulants such as alcohol, caffeine, and nicotine in the hours before bedtime; and creating a dark, comfortable and quiet sleeping environment.

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