Phone use after 10 pm linked to shorter teen sleep: JAMA study
Representative image: Sammy-Sander / Pixabay
A JAMA Pediatrics study published October 19, 2026 links teens' phone use after 10 pm to later, shorter sleep and pre-sleep use to night waking.
What Happened
A study published online in the journal JAMA Pediatrics on Monday, 19 October 2026 found that teenagers who used their smartphones after 10 pm fell asleep later, woke later and slept less in total. The researchers, Yihong Zhao, Lauren Hale and Dimitri Christakis, also found that phone use in the last few minutes before sleep was linked to more time awake during the night, mainly in the first half hour after falling asleep. According to the research team's release, that effect almost disappeared when teenagers put their phones down 20 minutes before sleep.
Key Facts
- The paper, "Evening Phone Use and Sleep Outcomes Among Youth", was published online by JAMA Pediatrics on 19 October 2026.
- It used data from the Adolescent Brain Cognitive Development (ABCD) Study, a large long-running study of young people in the United States.
- Phone use was recorded automatically by an app on participants' Android phones, and sleep was measured by Fitbit wrist trackers, rather than relying on what teenagers remembered.
- Data were collected between November 2020 and February 2024; the research team's release says about 425 teenagers were included.
- More total phone use after 10 pm was associated with later sleep onset, later waking and shorter total sleep.
- Use in the final minutes before sleep was associated with more "wake after sleep onset", meaning time spent awake after first falling asleep, mostly in the first 30 minutes.
- According to the release, that night-time waking was driven mostly by use in the final five minutes and became negligible when phones were put away 20 minutes before sleep.
- Dimitri Christakis, one of the three authors, is editor-in-chief of JAMA Pediatrics.
Why It Matters
Sleep is one of the first things to give way for students and young people juggling classes, coaching, part-time work and an active online life. Teenagers generally need more sleep than adults, and short or broken sleep is linked to poorer concentration, low mood and weaker performance. The phone is now the last thing many young people look at before they close their eyes, so how it affects sleep is a practical question for millions of families.
What makes this study useful is how the information was gathered. Many earlier studies asked teenagers to report their own screen time and sleep, which people tend to remember inaccurately. Here, the phone app logged actual use minute by minute, and the Fitbit recorded when each teenager fell asleep, woke and lay awake. That allowed the researchers to separate two different patterns: how much the phone was used late in the evening, and what happened in the minutes just before sleep.
The study found that the two patterns were linked to different problems. Heavy use after 10 pm pushed the whole night later and shortened it. Use right up to the moment of sleep was linked to a more restless start to the night. The authors describe these as different aspects of sleep, which suggests that cutting late-night scrolling and creating a short phone-free gap before sleep may each matter in their own way.
The findings show associations, not proof that the phone caused the poorer sleep. The participants were American teenagers who used Android phones, so the results may not apply equally to every group, and earlier research on bedtime screen use has not always agreed. Readers should also note that one of the three authors is the editor-in-chief of the journal that published the paper.
Impact
Short-term: The finding gives students and parents a simple, specific idea to discuss: keep the phone away for the last 20 minutes before sleep, and limit use after 10 pm, especially on school or college nights.
Long-term: Because the study used automatic tracking rather than self-reports, it adds to the evidence that schools, doctors and policymakers draw on when they write guidance on young people's screen use and sleep.
Who is affected: Teenagers and young adults who use phones late at night, parents setting household rules, hostel and college residents, and doctors and counsellors who advise young people on sleep.
Key Takeaway
A JAMA Pediatrics study of 19 October 2026 links teenagers' phone use after 10 pm to later, shorter sleep, and use in the final minutes before bed to more night-time waking.
Questions and Answers
What did the JAMA Pediatrics study on evening phone use and sleep find?
Published on 19 October 2026, it found that teenagers who used smartphones more after 10 pm fell asleep later, woke later and slept less, and that phone use in the last minutes before sleep was linked to more time awake in the first 30 minutes of the night.
Does putting the phone away before bed help, according to the study?
The research team said the extra night-time waking was driven mostly by phone use in the final five minutes before sleep and became negligible when teenagers stopped using their phones 20 minutes before sleeping.
How was phone use and sleep measured?
An app on participants' Android phones logged their actual phone use, and Fitbit wrist trackers recorded when they fell asleep, woke and were awake at night. The data came from the US-based Adolescent Brain Cognitive Development Study.
Does the study prove phones cause poor sleep?
No. It shows an association between phone use and sleep patterns, not cause and effect, and it covered American teenagers with Android phones, so results may differ in other groups.
Disclaimer: Prepared by the Peepals newsroom from publicly available sources with AI assistance. Information is accurate to the best of our knowledge at the time of publication and may change. Images may be representative. Not professional advice. Report an error via our contact page.
Sourced and fact-checked by the Peepals Global Editorial Team
Reported, fact-checked and published by the Peepals Global Editorial Team.
