Increased screen time for 1-year-old boys may be associated with higher instances of autism spectrum disorder (ASD) at 3 years of age, according to research published in JAMA Pediatrics.
Researchers conducted a large birth cohort study consisting of 84,030 mother-child dyads. They surveyed participants regarding their child’s screen time habits over the course of 2 separate analyses conducted at age 1 and age 3. Investigators also identified children who were diagnosed with ASD at age 2 or older.
Overall, 330 children received a diagnosis of ASD (0.4%). Among those diagnosed with the disorder, 76.0% were boys. Most mothers reported they allowed their children less than 1 hour of access to screen time, followed by responses of 1 to less than 2 hours, 2 to 4 hours, no screen time, and more than 4 hours (n=27,707, n=25,027, n=16,560, n=8541, and n=5402, respectively) at age 1. A total of 90% of the children had been exposed to screens by 1 year of age.
Boys with 1 to less than 2 hours of screen time (29.6%) had 2 times the risk of ASD compared with boys with no screen time (OR 2.16; 95% CI, 1.13-4.14; P =.02). Boys with at least 2 hours of screen time had 3 times the risk (19.6%; OR 3.48; 95% CI, 1.83-6.65; P <.001 for 2 to 4 hours, and 6.5%; OR 3.02; 95% CI, 1.44-6.34; P =.04 for 4 hours or more).
Investigators did not observe this association in girls.
A trend test revealed an association between screen time at 1 year of age and screen time at 3 years of age after adjusting for potential confounders such as maternal maltreatment or a child’s predisposition to ASD (based on Ages and Stages Questionnaire (ASQ-3) testing). Screen time exposure at 3 years of age was not associated with ASD.
“Even after accounting for predisposition to ASD at 1 year of age and maternal maltreatment factors, longer screen time at 1 year of age was associated with ASD at 3 years of age in boys,” according to the researchers. “With the rapid increase in the use of devices, it is necessary to review its health effects on infants and control excessive screen time.”
Limitations of the study include possible reporting bias due to reliance on self-reporting, failure to account for potential genetic and environmental confounding factors, and possible failure to account for mild cases of ASD.
Kushima M, Kojima R, Shinohara R, et al. Association between screen time exposure in children at 1 year of age and autism spectrum disorder at 3 years of age: the Japan environment and children’s study. JAMA Pediatr. Published online January 31, 2022. doi: 10.1001/jamapediatrics.2021.5778