Study links late-night phone use to sleep issues

A new study published in JAMA Pediatrics found that using smartphones late at night significantly delays the time it takes for adolescents to fall asleep and reduces the total amount of sleep they get. Researchers used smartphone apps and Fitbit devices to track actual phone use and sleep patterns, instead of asking participants to self-report their habits.

Phone use delays sleep onset

The study found that 30 minutes of phone use after 10 p.m. caused an average 26-minute delay in falling asleep. Participants also woke up 11 minutes later and slept about 13 minutes less overall compared to nights with no late-night phone use.

Final minutes before sleep are most disruptive

The final minutes before sleep were particularly impactful. Adolescents who used their phones in the five minutes before bed experienced more disturbances at the beginning of their sleep period, making it harder for them to settle down.

Social media dominates late-night phone activity

Social networks such as TikTok, YouTube, and Snapchat were among the most accessed apps during late hours. After 8 p.m., adolescents spent an average of 44 minutes per evening on these platforms, indicating a strong link between social media and late-night screen time.

Experts highlight more than just screen light

Dr. Daniel Bigman, a child and adolescent psychiatrist and sleep specialist, explained that the problem is not just the light from screens but also the stimulating effects of videos, messages, and social media content. These elements send sensory signals to the brain, keeping it active when the body should be winding down for sleep.

Sleep deprivation affects mental and physical health

Repeated lack of sleep can lead to increased stress and anxiety, decreased motivation, daytime sleepiness, and difficulties with impulse control and decision-making. These effects highlight the importance of managing screen time, especially for adolescents.