One hour’s screen use after going to bed increases your risk of insomnia by 59%, scientists find

(Press-News.org) Scientists have found another reason to put the phone down: a survey of 45,202 young adults in Norway has discovered that using a screen in bed drives up your risk of insomnia up by 59% and cuts your sleep time by 24 minutes. However, social media was not found to be more disruptive than other screen activities. 

“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, lead author of the article in Frontiers in Psychiatry. “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.” 

Night night, sleep tight? 

Sleep is critical to our mental and physical health, but many of us don’t get enough. At the same time, an increasing number of people are accustomed to using screens in bed, which may be associated with poor sleep. Screen use is thought to impact sleep in four ways: notifications disturb sleep, screen time replaces sleeping time, screen activities keep you wakeful so you take longer to fall asleep, or light exposure delays circadian rhythms.  

“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.” 

To investigate, the scientists used the 2022 Students’ Health and Wellbeing survey, a nationally representative study of Norwegian students. They reached 45,202 participants in full-time higher education, aged between 18-28 years old.  

They first asked participants to say whether they used screens after going to bed and for how long. Then they asked participants to identify their chosen activities: watching shows or movies, gaming, social media, surfing the internet, listening to audio like podcasts, or reading study-related materials.  

Participants were also asked to report their bedtime and rising time, as well as how long it took them to fall asleep, how often they had trouble falling or staying asleep, how often they felt sleepy during the day, and how long their sleep problems persisted. Insomnia was defined as trouble sleeping and daytime sleepiness issues at least three times a week over at least three months.  

The scientists then sorted responses into three categories: one where participants said they only used social media, one where participants did not mention social media, and one where participants selected several activities, including social media.  

All-nighters 

The scientists found that increasing screen time after bedtime by one hour increased the odds of insomnia symptoms by 59% and lowered sleep duration by 24 minutes. However, using social media wasn’t more detrimental than other screen activities. There was no significant interaction between the time spent using a screen and the choice of activity, suggesting that the activity itself didn’t affect the amount of time people stayed awake. This indicates that screens reduce sleep time because they displace rest, not because they increase wakefulness: different activities would be expected to affect wakefulness differently.    

“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,” suggested Hjetland. “If you do use screens, consider disabling notifications to minimize disruptions during the night.”  

The scientists cautioned, however, that their study focuses on a single culture. There could be notable differences in the relationship between screen use and sleep globally. Additionally, to compare social media use with other screen activities, some activities which could have different effects on sleep — such as listening to music or gaming — were included in a single category.  

“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.” 

END