Associations between types of screen use and bedtimes among a large sample of adolescents: Age and bedtime specific variations from the COMPASS study

Background Screen time is linked to poorer sleep among adolescents. However, most evidence focuses on total recreational screen time rather than on time spent on different screen-based activities. Also, few studies have specifically examined bedtime, an actionable determinant of adolescent sleep hygiene. To date, it is not clear how age and chronotype influence this relationship. The objective of this study was to examine the associations between time spent on different screen-based activities and adolescents’ bedtimes. We also aimed to examine how these associations vary based on age and chronotype. Methods Using a cross-sectional design, we analyzed data from 67,710 adolescents attending 154 Quebec schools in 2025 as part of the COMPASS study. Quantile regressions were conducted to assess associations between the time adolescents spend on different screen-based activities (i.e., surfing social media, playing video games, sending messages, browsing the Internet, watching/streaming television shows or movies) and their bedtime. The analyses were stratified by age and chronotype and adjusted for the adolescents’ sex and family-level material affluence. A difference-in-difference analysis was also conducted. Results Each type of recreational screen activity was positively associated with later bedtimes. Compared with adolescents who used screens ≤ 1 hour per day, those reporting more than 3 hours of screen use had bedtimes occurring approximately 45 minutes later for social media use, video gaming, and messaging, and about 30 minutes later for Internet browsing and television viewing. The difference in bedtime associated with higher versus lower screen use (≤ 1 hr vs. > 3 hrs/day) was greater among younger adolescents (11–12 years) than older ones (≥ 15 years), except for video gaming. The difference in bedtime associated with higher versus lower screen use (≤ 1 hr vs. > 3 hrs/day) was greater among late sleepers than early sleepers. Conclusions Each type of recreational screen activity among adolescents is associated with later bedtimes. Younger adolescents and late sleepers appear more susceptible to additional bedtime delays, which may ultimately influence their quantity and quality of sleep. This study offers important insights for the development of interventions and recommendations that target more vulnerable adolescents to promote healthy sleep, an essential component of adolescent health.