Whether it's reading a book, having a shower or putting on some music, many of us have some kind of ritual – small or large – that we do before lights out. And while we have a feel for the good and the bad, we often don't really know just how detrimental some bedtime habits might be for our sleep. Now, for one particular activity, we do.
It's well known and backed by science that screen-time before bed is not the best habit – even if some of us prefer to fall asleep in the company of a TV screen. And it's not the first study to look at smartphone screen time, either. There's a body of scientific evidence that suggests electronic screens are not helpful for sleep length or quality (though some studies have countered this). But in broad survey-based research out of the Norwegian Institute of Public Health, data turned up some surprising figures into just how much phones in bed impact sleep.
In the study, 45,202 people were asked specific questions about their phone screen time and sleep habits and found a significant link between more pillow viewing or scrolling and an increase in insomnia symptoms. And yes, while part of it is that if you spend an hour on your phone after you turn the lights out that this is cutting into the time you'd normally be asleep, that's not the entire picture here.
The researchers found that an hour of phone use in bed increases risk of insomnia by 59% and shaves 24 minutes off your night's sleep. And while the study was on older university students aged 18-28, social media was not the driving force - any phone use had the same impact.
“The type of screen activity does not appear to matter as much as the overall time spent using screens in bed,” said Dr. Gunnhild Johnsen Hjetland of the Norwegian Institute of Public Health, and the study's lead author. “We found no significant differences between social media and other screen activities, suggesting that screen use itself is the key factor in sleep disruption – likely due to time displacement, where screen use delays sleep by taking up time that would otherwise be spent resting.”
As someone who is guilty of "relaxing" after the lights are out by scrolling my algorithmically driven news and political content on TikTok, I can say anecdotally that it does impact how much sleep I get and how less rested I feel when I need to wake up (particularly if I've fallen asleep with the app open and it's stuck looped on that single video all night). But that's, of course, not robust research. However, it does suggest that it's not necessarily just a habit of young people.
And there are a host of known reasons for how screens can impact sleep – notifications, how interacting with the phone encourages wakefulness so it takes longer to fall asleep, and the light interfering with circadian rhythms that drive the day/night cycle.
“Sleep problems are highly prevalent among students and have significant implications for mental health, academic performance, and overall well-being, but previous studies have primarily focused on adolescents,” said Hjetland. “Given the widespread use of screens in bed we aimed to explore the relationship between different screen activities and sleep patterns. We expected that social media use might be more strongly associated with poorer sleep, given its interactive nature and potential for emotional stimulation.”
The questionnaire asked participants about how much time they'd spend using their phone after getting into bed, and what they were doing on the phone: watching TV shows or movies, playing games, using social media, browsing the web, listening to podcasts, or reading study-related material. And because the researchers thought social media was a leading driver of bedtime phone use, they grouped responses into three categories: participants who said they only used social media, participants who did not mention social media, and participants who listed several activities, including social media.
There were also questions about the participants' bedtime and waking time, how long it took them to get to sleep, if they has trouble falling and staying asleep, how they felt during the day, and how long any restlessness persisted. Daytime sleepiness and trouble sleeping at night for three or more times per week was considered insomnia.
Overall, an extra hour on the screen in bed resulted in the aforementioned 59% increased risk of insomnia, and that loss of 24 minutes a night. But activities across the board supported wakefulness. The good news is that this doesn't have to be permanent, and people can work to get their sleep back on track by – you guessed it – putting the phone down.
“If you struggle with sleep and suspect that screen time may be a factor, try to reduce screen use in bed, ideally stopping at least 30-60 minutes before sleep,” said Hjetland. “If you do use screens, consider disabling notifications to minimize disruptions during the night.”
There are, of course, limitations to this study. The researchers couldn't determine if some activities, such as gaming or the type of content being viewed, led to distinctly different impacts on sleep. Nor did it take into account other factors such as mental health, external impacts, diet or other factors that influence sleep quality. Nor does it compare phone screen time to other bedtime activities like reading or watching TV.
“This study cannot determine causality – for example, whether screen use causes insomnia or if students with insomnia use screens more,” noted Hjetland. “The study also did not include physiological assessments, which could provide more precise insights into sleep patterns.”
Nonetheless, such a large population study does suggest screens in bed are more detrimental to both quantity and quality of sleep, and may help those who use this time to "catch up" on leisure activities recognize it could be doing more harm than good. Further studies are needed.
The study was published in the journal Frontiers in Psychiatry.
Source: Norwegian Institute of Public Health via Scimex
