Scientists Reveal How Much an Hour’s Screen Time in Bed Could Cost You

Sleep specialists have long warned of the hazards of bringing smartphones into the bedroom. Now, research has confirmed just how damaging that habit can be.

The new study, which surveyed more than 45,000 university students in Norway, found that late-night screen was associated with a significant reduction in sleep quality and duration.

Moreover, spending just one hour on a screen after going to bed was linked to a 59 percent increase in the risk of insomnia.

Despite its reputation as a big bad of modern technology, scrolling through social media was not found to be more disruptive than other screen-based activities.

“The type of screen activity does not appear to matter as much as the overall time spent using screens in bed,” paper author Gunnhild Johnsen Hjetland of the Norwegian Institute of Public Health said in a statement.

“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.”

The findings highlight a growing disconnect between technology use and sleep hygiene among young adults. While it is widely understood that sleep is critical to mental and physical health, modern bedtime routines increasingly include screens, apps and notifications—all of which may keep the brain on high alert long after lights out.

“Sleep problems are highly prevalent among students and have significant implications for mental health, academic performance, and overall well-being,” Hjetland said. “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.”

Other sleep experts might agree; in fact, Chelsie Rohrscheib, a neuroscientist and sleep specialist who serves as head of sleep at Wesper, told Newsweek that doomscrolling—the compulsive consumption of negative news online—can set off an intense physiological chain reaction in the brain.

In their study, researchers drew on data from the 2022 Students’ Health and Wellbeing survey, a nationally representative health study of full-time higher education students in Norway aged 18 to 28.

Participants were asked about their bedtime screen habits, including how long they used screens after going to bed and which activities they chose—from watching movies to browsing, studying or listening to audio content.

Researchers then measured those responses against self-reported sleep metrics, including their average bedtime and wake up time, their difficulty falling or staying asleep, daytime drowsiness and whether those symptoms had persisted for three months or more.

The results were unambiguous: more screen time correlated with less sleep, but social media was not the culprit alone.

An additional hour of post-bedtime screen was associated with an increased in the risk of insomnia symptoms of 59 percent and a shortened sleep duration of an average of 24 minutes. Contrary to their expectations, researchers found no statistical difference between social media and other screen-based activities.

The findings point to “time displacement,” rather than emotional stimulation or content type, as being the main reason why an extra hour online can be harmful to sleep.

“If screen use displaces time that could otherwise be used for sleep, this may explain the reduction in sleep duration,” said Hjetland.

How To Unwind at Night

Hjetland added that while the study design could not determine causality, the results still support a clear takeaway: if you are not sleeping well, it might be time to rethink taking screens to bed with you.

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

Talking about doomscrolling in particular, Rohrscheib added that the practice “raises your stress levels, which may lead to activation of your amygdala, the area of your brain responsible for the stress response. This in turn activates your sympathetic nervous system, which places you in a state of fight or flight.”

That stress response releases cortisol and adrenaline, both of which are “extremely stimulating. This makes it very difficult to fall asleep and stay asleep.”

In addition to the biochemical reaction, the act of consuming distressing content—especially at the end of the day—can cause hyperfocus and anxiety, trapping the brain in a feedback loop that blocks natural rest.

“Consuming stressful information causes hyperfixation and a racing mind, which makes it nearly impossible for your brain waves to slow down and initiate the sleep process,” Rohrscheib said.

To minimize harm, Rohrscheib recommends adopting a nightly wind-down ritual, ideally beginning one to two hours before bed.

“Ideally, you should consider a pre-bedtime routine that focuses on reducing stress and relaxing,” she said. “This includes putting away your electronic devices.”

As screen use continues to surge across generations and devices, the new findings may offer a simple, science-backed step toward better sleep: turn off the phone, turn down the lights and let your brain and body rest.

Newsweek reached out to Hjetland for further comment via email.

Is there a health issue that’s worrying you? Let us know via health@newsweek.com. We can ask experts for advice, and your story could be featured on Newsweek.

Reference

Hjetland, G, J., & Sivertsen, B. (2025). How and when screens are used: Comparing different screen activities and sleep in Norwegian university students. Frontiers in Psychiatry. http://dx.doi.org/10.3389/fpsyt.2025.1548273.