Many are concerned about the downstream effects of the widespread use of digital media by children and adolescents. Critics have speculated that excessive screen time leads to violence, bullying, loneliness, increased rates of depression and anxiety, sleep disruption, and cognitive problems. However, studies investigating the potentially deleterious effects of screen time have been difficult to conduct and have yielded mixed results. In a recent study, Henry Onyeaka, MBChB, MPH, a PGY-3 Psychiatry resident in the Mass General/McLean program and colleagues, analyzed data from the 2017 and 2019 Youth Risk Behavior Survey to investigate the association between screen time and cognitive deficits in adolescents.
The Youth Risk Behavior Survey queries a nationally representative sample of adolescents attending school in the United States. For this study, the researchers analyzed data from 17,076 adolescents completing the 2017 and 2019 survey. Participants were asked about their screen time: “On an average school day, how many hours do you play video or computer games or use a computer for something that is not schoolwork?” The outcome variable was self-reported cognitive difficulties: “Because of a physical, mental, or emotional problem, do you have serious difficulty concentrating, remembering, or making decisions?”
In this group of 17,076 adolescents (50.2% female), about one in three (34.1%) reported cognitive difficulties. The average number of hours of screen time on an average school day was 4.11 hours, and 45% of the adolescents engaged in excessive screen-time behaviors (defined as 3 or more hours) on an average school day.
After adjusting for potential confounding variables, the odds of reporting cognitive difficulties was 1.28 times higher for adolescents who engaged in excessive screen-time behaviors compared to adolescents who did not engage in excessive screen-time behaviors (AOR = 1.28, 95% CI = 1.18-1.40). Similarly, each additional increase in the number of hours of screen-time behaviors increased the odds of subjective cognitive difficulties by 1.05 (AOR = 1.05, p < .001, 95% CI = 1.03–1.08).
Lingering Questions
While this study indicates that excessive screen time is associated with increased risk of cognitive difficulties, there are some important complexities to consider. In this sort of cross-sectional survey, it is possible to identify a correlation but impossible to establish causation. Rather than causing cognitive difficulties, it is possible that children with cognitive difficulties may be more likely to enjoy using devices for longer periods of time or may have difficulty curbing their use. However, other studies have raised concerns that chronic sensory stimulation from screen exposure may result in structural brain changes with potentially negative cognitive consequences in the developing brain (Paulus MP et al, 2019).
While we may not be able to establish a causal link between excessive screen time and cognitive difficulties, it is striking to note that, on average, adolescents are spending four hours per day on a device, and nearly half of the kids in this age group report spending more than three hours each day. One must take into consideration not only the negative effects of this exposure but also the absence of other activities– unstructured time, sports, outdoor activities, reading, hobbies, family time — that kids have less time to pursue.
Randomized controlled trials are not available to help us answer this question, yet understanding how screen time, particularly social media, affects children and adolescents, is a pressing question. Devices are here to stay.
Read More
Onyeaka HK, Muoghalu C, Baiden P, Okine L, Szlyk HS, Peoples JE, Kasson E, Cavazos-Rehg MSWP, Firth J, Torous J. Excessive screen time behaviors and cognitive difficulties among adolescents in the United States: Results from the 2017 and 2019 national youth risk behavior survey. Psychiatry Res. 2022 Oct; 316:114740. doi: 10.1016/j.psychres.2022.114740.
