(© Point of view - stock.adobe.com)
In a nutshell
Using screens in bed for just one hour increases insomnia risk by 59% and reduces sleep duration by 24 minutes, regardless of the type of screen activity.
Contrary to expectations, students who exclusively used social media in bed reported better sleep than those using other screen activities, suggesting total screen time matters more than the specific activity.
Students who avoided using screens in bed altogether had 24% lower odds of experiencing insomnia symptoms compared to screen users.
OSLO, Norway — Using a smartphone or tablet for just one hour after going to bed raises the risk of insomnia by 59%, according to new research. This finding comes from one of the largest studies conducted on screen use and sleep among university students, highlighting how our nightly digital habits may be robbing us of crucial rest.
Researchers from the Norwegian Institute of Public Health examined data from over 45,000 university students and found that each additional hour spent using screens after going to bed not only significantly increased insomnia risk but also cut sleep duration by about 24 minutes. What’s particularly notable is how consistent this effect appears to be—regardless of whether students were scrolling through social media, watching movies, or gaming.
The Digital Bedtime Crisis
Sleep problems have reached concerning levels among university students globally. The study reports that about 30% of Norwegian students sleep less than the recommended 7-9 hours per night. Even more troubling, over 20% of male students and 34% of female students report sleep issues meeting clinical criteria for insomnia, numbers that have been rising in recent years.
Smartphones have transformed our bedrooms into entertainment centers. Previous research shows that over 95% of students use screens in bed, with an average screen time after going to bed of 46 minutes. Some studies have even found that 12% of young adults engage with their smartphones during periods they’ve self-reported as sleep time.
Many sleep experts have speculated that social media might be especially harmful for sleep compared to more passive activities like watching television. The reasoning seems logical – social media platforms are designed to keep users engaged through interactions, notifications, and endless scrolling features that make it difficult to disconnect. Plus, the social obligations and fear of missing out associated with platforms like Instagram and TikTok might make users more reluctant to put their devices away at bedtime.
Using your phone in bed can completely derail your odds of getting a healthy amount of sleep. (© leungchopan – stock.adobe.com)
Surprising Findings Challenge Common Beliefs
Researchers divided participants into three groups: those who exclusively used social media in bed (about 15% of the sample), those who used social media combined with other screen activities (69%), and those who engaged in non-social media screen activities only (15%).
Contrary to expectations, students who exclusively used social media in bed reported fewer insomnia symptoms and longer sleep duration compared to the other groups. The non-social media group experienced the highest rates of insomnia and shortest sleep duration, while those mixing social media with other activities were intermediate.
This unexpected outcome challenges the notion that social media is uniquely harmful to sleep. Instead, the research points to the total time spent on screens in bed, regardless of the specific activity, as the strongest predictor of sleep problems. Each additional hour of screen time after going to bed was consistently associated with poorer sleep outcomes across all three groups.
Why might social media-only users sleep better? Researchers propose that exclusively using social media might reflect a preference for socializing and maintaining connections with others, which generally protects against sleep problems. Being socially engaged has been linked to better sleep in numerous studies.
Alternatively, those experiencing the most sleep difficulties might deliberately avoid social media before bed, instead turning to activities like watching movies or listening to music as sleep aids. Many people with insomnia use screen-based activities to distract themselves from negative thoughts or anxiety that prevent sleep.
What This Means For Your Sleep
The study, published in Frontiers in Psychiatry, reveals how screens affect sleep through several pathways: direct displacement (screen time replacing sleep time), light exposure (suppressing melatonin production), increased mental arousal (making it harder to fall asleep), and sleep interruption (notifications disturbing sleep).
The findings from this study largely support the displacement hypothesis. If increased arousal from interactive content were the main factor, we would expect to see different associations between sleep and various screen activities. Instead, the consistent relationship between screen time and sleep problems across activity types indicates that simply spending time on screens—time that could otherwise be spent sleeping—may be the most important factor.
For university students already struggling with academic pressure, social adjustment, and mental health challenges, poor sleep represents an additional burden with potentially serious consequences. Sleep deprivation impairs attention, memory, and other cognitive functions crucial for academic success.
Non-screen users had 24% lower odds of reporting insomnia symptoms, confirming that keeping devices out of the bedroom is a worthwhile sleep hygiene practice. Even if it’s not a complete solution to sleep difficulties, it represents a behavior that could meaningfully improve sleep for many young adults.
“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,” says lead author, Dr. Gunnhild Johnsen Hjetland, in a statement. “If you do use screens, consider disabling notifications to minimize disruptions during the night.”
The next time you’re tempted to bring your phone to bed “just to check a few things,” remember the Norwegian students’ experience: each hour spent on that screen, regardless of what you’re doing, might cost you 24 minutes of precious sleep and significantly increase your chances of developing insomnia. Given what we know about the essential role of sleep in physical and mental health, learning, and overall wellbeing, that’s a trade-off worth reconsidering.
Paper Summary
Methodology
This study analyzed data from the Students’ Health and Wellbeing Study (SHOT2022), a national cross-sectional survey of Norwegian higher education students. Data collection occurred from February to April 2022, with a focus on full-time students between 18 and 28 years old. The survey gathered information on demographics, sleep patterns, and screen use behaviors from 59,544 participants (a 35.1% response rate), with 45,202 meeting the age criteria for analysis. Participants completed web-based questionnaires after providing electronic informed consent. The research team created three distinct groups based on screen activities: those exclusively using social media, those using social media plus other activities, and those using only non-social media screen activities. They calculated average screen time in bed by multiplying reported time spent per night by the number of nights per week using screens, then dividing by seven. Sleep metrics included self-reported insomnia symptoms (based on DSM-5 criteria), sleep duration, time in bed, sleep onset latency, and wake time after sleep onset. The researchers used multiple logistic regression to assess the relationship between screen time and insomnia, and multiple linear regression to analyze associations with sleep duration, with adjustments for age and sex.
Results
The study revealed that 87.2% of students used screens in bed, with women more likely to do so than men (88.9% vs. 83.8%). Among screen users, most (69%) combined social media with other activities, while approximately 15% used only social media and another 15% engaged exclusively in non-social media activities. The analysis showed that each additional hour of screen time in bed was associated with 59% higher odds of experiencing insomnia symptoms and a reduction in sleep duration of 24 minutes. Importantly, these associations remained consistent across all three activity groups, suggesting the type of screen activity didn’t significantly affect sleep outcomes. However, independent of screen time, those who exclusively used social media had lower rates of insomnia (27.6%) compared to the mixed activity group (35.3%) and the non-social media group (37.1%). They also enjoyed longer average sleep duration (7.76 hours) compared to the mixed (7.56 hours) and non-social media groups (7.38 hours). Students who didn’t use screens in bed at all had 24% lower odds of reporting insomnia symptoms compared to screen users, though there was no significant difference in sleep duration between users and non-users.
Limitations
The researchers acknowledged several important limitations that should be considered when interpreting their findings. First, the cross-sectional design only shows associations between variables and cannot establish causality—it’s possible that people with existing sleep problems use screens as a way to cope rather than screens causing the sleep difficulties. Second, the moderate response rate of 35.1% may have introduced selection bias, potentially affecting the representativeness of the sample. Third, all measures relied on self-reported data without objective verification through methods like polysomnography or activity tracking, which may introduce recall bias or inaccuracies. Fourth, the screen activity categories were quite broad and may have encompassed a wide range of experiences and content types within each group. For example, social media encompasses many different platforms with varying levels of interactivity and engagement, while non-social media activities could include anything from passive TV watching to intense gaming. Finally, the study didn’t consider screen use that occurred after initially falling asleep, which might be particularly relevant for those who receive notifications throughout the night or check their devices during periods of nighttime wakefulness.
Funding and Disclosures
The lead author’s postdoctoral position was funded by the DAM Foundation (grant number 2021/FO347287), though the foundation had no involvement in study design, data collection, analysis, interpretation, or manuscript preparation. One of the study authors, Michael Gradisar, disclosed employment with WINK Sleep Pty Ltd. and Sleep Cycle AB, which could potentially represent a conflict of interest. However, the remaining authors declared no commercial or financial relationships that might influence the research. The study was conducted in collaboration with three major Norwegian student welfare organizations (SiO, Sammen, and SiT), which initiated and designed the SHOT study that provided the data.
Publication Information
This study, titled “How and when screens are used: comparing different screen activities and sleep in Norwegian university students,” was published in Frontiers in Psychiatry on March 31, 2025. The research was conducted by Gunnhild Johnsen Hjetland, Jens Christoffer Skogen, Mari Hysing, Michael Gradisar, and Børge Sivertsen, representing institutions including the Norwegian Institute of Public Health, Stavanger University Hospital, University of Bergen, WINK Sleep Pty Ltd., Sleep Cycle AB, and Fonna Health Trust.