JNS: A groundbreaking study from the University of Otago has upended conventional wisdom regarding screen time and its effect on youth sleep. Contrary to established sleep guidelines that recommend no screen use within an hour or two before bedtime, researchers have found that the timing of screen use—specifically, screen use while in bed—has a more significant impact on sleep than the duration of screen exposure.
The study, published in JAMA Pediatrics, highlights a key finding: while screen time in the two hours preceding bedtime had minimal effect on sleep quality, the use of screens once in bed was notably disruptive. Dr. Bradley Brosnan, lead author from the Edgar Diabetes and Obesity Research Centre, emphasized that screens are deeply embedded in adolescents’ nighttime routines, suggesting a need for updated guidelines that reflect modern practices.
In the study, 85 adolescents aged 11 to 14 wore body cameras for a week to monitor their screen use from three hours before bed until they were actually in bed. A secondary infrared camera tracked screen use within their bedrooms, while an actigraph measured their sleep.
The results revealed that nearly all participants used screens in the two hours before bed, but more than half continued screen use once in bed. Alarmingly, one-third of the participants engaged with screens after initially attempting to sleep.
Dr. Brosnan noted that screen time before getting into bed had minimal impact on the night’s sleep. In contrast, screen use while in bed delayed sleep onset by about 30 minutes and reduced overall sleep duration. The study found that interactive activities, such as gaming and multitasking across multiple devices, had the most detrimental effects. Each additional 10 minutes of such screen time corresponded to a similar reduction in sleep duration.
The research suggests that the primary issue is not the direct effects of blue light or interactive engagement but rather the displacement of time, which delays sleep onset.
Dr. Brosnan advocates for revising sleep guidelines to better align with contemporary lifestyles. “A more practical guideline would involve keeping devices out of the bedroom,” he said. “This approach would allow adolescents to use their devices before bedtime but prevent screen use once they are in bed.”
In response to these findings, Dr. Brosnan has been working on screenwise.co.nz, an online platform aimed at providing evidence-based strategies for managing screen time at home. He is also actively engaging with local schools to educate parents and communities on fostering healthier screen habits.
“Screenwise offers realistic, practical tips for integrating better screen management into daily routines,” Dr. Brosnan explained. “Our goal is to help families improve sleep and overall well-being through informed, achievable changes.”
