A recent study from the University of Otago reveals that it’s not the screen activities themselves, but the timing of screen use in the evening, that adversely affects the sleep of adolescents.
Current recommendations suggest avoiding screens for one to two hours prior to sleep. However, this research indicated that using screens within those two hours had minimal effects on sleep; the real issue arose from using screens while actually in bed.
According to Dr Bradley Brosnan, the lead author from the Edgar Diabetes and Obesity Research Centre, screens have become an integral part of many teenagers’ bedtime routines, and it may be time to reassess sleep guidelines to align with contemporary lifestyles.
The findings, published in JAMA Pediatrics, involved 85 participants aged 11 to 14 who wore body cameras for three hours prior to bedtime until they actually went to bed, over the span of one week.
While the body cameras tracked their screen usage, an additional infrared camera was set up in their bedrooms to monitor screen time while they were in bed. Participants also wore an actigraph, a small device that tracks sleep patterns.
“We quickly noticed that adolescents tend to engage in a lot of their screen time while in bed,” Dr Brosnan mentioned.
Research findings showed that 99 percent of participants used screens in the two hours before bedtime, over half did so while in bed, and a third used them after initially attempting to sleep.
“The most intriguing discovery was that screen time prior to going to bed had minimal influence on that night’s sleep.
“In contrast, screen usage once in bed did disrupt their sleep, delaying them from falling asleep by about half an hour and decreasing their total sleep duration.”
This impact was especially pronounced for engaging activities like gaming and using multiple devices simultaneously—such as streaming a movie on a laptop while playing a game on a console.
“For every extra 10 minutes spent on such activities, sleep duration was reduced nearly equivalently,” he noted.
“Our results imply that the effect of screen time on sleep stems mainly from delayed sleep onset, rather than any direct influence from blue light or interactive activity, as we saw no correlation between screen use and sleep latency or wakefulness during sleep.”
Dr Brosnan advocates for a straightforward sleep guideline, which although practical in theory, may not reflect reality: keeping devices out of the bedroom. This allows teens to engage with their devices prior to bed, without bringing them into bed.
“It’s crucial to reassess sleep guidelines so they are relevant to our current reality, as the existing ones are neither feasible nor suitable for modern lifestyles.”
