The analysis found “a consistent pattern of effect across a range of countries and environments,” said Dr. Ben Carter, lead author and assistant professor of biostatistics at King’s College London.
Carter and colleagues reviewed the medical literature to identify hundreds of useful studies conducted between January 1, 2011 and June 15, 2015. They selected 20 research reports involving a total of 125,198 children evenly divided by gender with an average age of 14 years. After extracting the relevant data, Carter and his co-authors performed their own meta-analysis.
Several parents will be surprised by the results: The team found a “strong and consistent link” between using media devices at bedtime and insufficient sleep, poor sleep quality, and excessive sleepiness during the day.
However, Carter and his team have surprisingly found that children who do not use their equipment in their bedrooms still have interrupted sleep and are likely to suffer from the same problems. The lights and sounds emitted by the technology, as well as the content itself, can be too stimulating.
Although Carter admits that the weakness of the analysis was “how the data were collected in the primary studies: parents and children report it,” many of us are likely to recognize the habits of our own families, which are reflected in the statistics.
According to Carter and his co-authors, this ubiquitous technology negatively affects children’s sleep by extending their sleep time because they are playing a movie or playing another game.
The light emitted from these devices can also affect the circadian rhythm, the biological processes of the timing of the internal clock, including body temperature and the release of hormones, the researchers explain. One specific hormone, melatonin, causes fatigue and contributes to the timing of our sleep and wake cycles. Electronic lights can delay the release of melatonin, disrupt this cycle and make it difficult to fall asleep.
Carter and his co-authors also suggest that online content can be psychologically stimulating and keep children and teens awake well after an hour when they turn off their devices and try to sleep.
“Sleep is vital for children,” said Dr. Sujay Kansagra, director of the pediatric sleep neurology program for sleep at Duke University Medical Center, who did not participate in the new analysis. “We know that sleep plays a vital role in brain development, memory, self-regulation, attention, immune function, cardiovascular health, and more.”
Kansagra said it is possible that parents did not adequately report children using the device at night, but that the technology was more likely to simply interfere with sleep hygiene. “For example, children who are allowed to keep the device in their room are more likely to avoid a good sleep routine that we know is useful for sleep,” he said.
Practicing proper sleep hygiene
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 that proves an association between ADHD and some sleep disorders. “
The findings of the new study are not surprising in many respects. “Sleep hygiene is strongly influenced by technology, especially during adolescence,” said Kline, who bases his opinion not only on research but also on his “personal experiences and anecdotes of many other sleep experts.”
Other recommendations for proper sleep hygiene include not exercising (physically or mentally) too close to bedtime; establishing a regular sleep plan; restriction of exposure to light before sleep; avoiding stimulants such as alcohol, caffeine and nicotine at bedtime; and creating a dark, comfortable and peaceful sleep environment.