This common activity is linked to 59% higher odds of insomnia, study finds

A large study of Norwegian college students has found that spending more time on screens after going to bed is tied to a higher likelihood of experiencing insomnia and getting less sleep — no matter the type of screen activity. For each additional hour spent on screens in bed, participants had 59% higher odds of reporting symptoms of insomnia and slept an average of 24 minutes less. Interestingly, students who used only social media in bed reported fewer insomnia symptoms and longer sleep duration than those who engaged in other screen-based activities.

The research was published in Frontiers in Psychiatry.

The researchers conducted this study to better understand how screen time after going to bed impacts sleep in young adults, a group known for high levels of digital media use and frequent sleep issues. While many past studies have focused on children and teenagers, the relationship between screens and sleep among college-aged adults has received less attention. The researchers also wanted to explore whether different screen activities — such as social media, watching videos, or gaming — affect sleep differently. Some experts have speculated that social media might be particularly harmful because of its stimulating and interactive nature, but evidence has been mixed.

To investigate these questions, researchers used data from the 2022 Students’ Health and Wellbeing Study, a national survey of higher education students in Norway. From this dataset, the researchers focused on a sample of 45,654 full-time students aged 18 to 28. These students answered detailed questions about their bedtime screen use, types of activities they engaged in, and their sleep patterns. About 38,800 of them reported using screens in bed, making up the core sample for the main analyses.

Participants were asked how often they used screens in bed, how long they spent on them each night, and what types of activities they did — such as checking social media, watching movies, listening to music, gaming, or reading for school. The researchers grouped participants into three categories based on their responses: those who used only social media, those who used social media along with other activities, and those who did not use social media but engaged in other screen-based tasks.

To measure sleep, the researchers collected information about bedtime and wake time for both weekdays and weekends. They also asked about how long it usually took to fall asleep, whether participants woke up during the night, and how often they felt tired during the day. Participants were classified as having symptoms of insomnia if they reported trouble falling or staying asleep at least three times per week, daytime sleepiness at least three times per week, and a duration of these issues lasting at least three months.

The findings confirmed a consistent pattern: more screen time in bed was linked to worse sleep. On average, each additional hour spent on screens after going to bed was associated with 59% greater odds of meeting the criteria for insomnia and 24 fewer minutes of sleep per night. These associations were statistically significant and remained consistent across all screen activity groups. In other words, whether a student was watching videos, scrolling social media, or doing something else on their device, more time on screens was associated with poorer sleep.

However, when the researchers looked more closely at the types of activities students engaged in, some differences emerged. Those who used only social media in bed had the best sleep outcomes overall — they were less likely to report symptoms of insomnia and had the longest sleep duration. Students who used a mix of social media and other activities fell somewhere in the middle. The group with the poorest sleep were those who used screens for activities other than social media. Compared to students who only used social media, those who engaged in other activities had 35% higher odds of reporting insomnia and slept about 17 minutes less per night.

These differences were observed even after accounting for the amount of time spent on screens. That is, the type of screen activity was linked to sleep outcomes independent of duration. Still, the main factor that seemed to matter most was the total time spent on screens in bed. The link between screen time and sleep problems did not vary significantly across the three activity groups.

The researchers offer several explanations for these findings. One possibility is that screen time reduces sleep simply because it replaces time that would otherwise be spent resting. This idea, known as the displacement hypothesis, is supported by recent research showing that screen use is more likely to delay bedtime than to directly cause problems falling asleep once in bed. If screen use increased arousal or disrupted the body’s sleep rhythms through light exposure, different activities might have shown different effects — but that was not the case here.

Another explanation is that students who only use social media in bed might be more socially connected, which can protect against sleep problems. Previous studies have found that strong social ties are associated with better sleep. It’s also possible that students with existing sleep difficulties are more likely to use other screen-based activities, like watching movies or listening to audio, to help pass the time or relax while trying to fall asleep. In this case, screen use may be a result of poor sleep rather than the cause.

It’s important to note that the study’s cross-sectional design means it cannot establish causation. The researchers cannot say for sure whether screen use causes insomnia or if people with insomnia are simply more likely to use screens. Longitudinal studies or experiments tracking screen use and sleep over time would be needed to clarify the direction of these effects. It’s also possible that certain personality traits, such as being a night owl, influence both screen use and sleep patterns.

Despite these limitations, the study adds important insight into how screen use at bedtime is related to sleep in young adults. It challenges the idea that social media is uniquely harmful and suggests that overall screen time may be the more important factor. The results support the idea that reducing screen use in bed — regardless of the activity — could help improve sleep.

Lead author Gunnhild Johnsen Hjetland of the Norwegian Institute of Public Health emphasized this point: “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.”

Hjetland also offered practical advice: “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 to 60 minutes before sleep. If you do use screens, consider disabling notifications to minimize disruptions during the night.”

The study, “How and when screens are used: Comparing different screen activities and sleep in Norwegian university students,” was authored by Gunnhild Johnsen Hjetland, Jens Christoffer Skogen, Mari Hysing, Michael Gradisar, and Børge Sivertsen.