Longer screen time at age 1 tied to autism risk

Boys who were exposed to screens for longer hours at 1 year of age have significantly increased risk of having autism spectrum disorder (ASD) at 3 years of age, suggest data from the The Japan Environment and Children’s Study.

“Amid the recent outbreak of the COVID-19 pandemic, there has been a rapid change in lifestyles, with electronic devices being used as the main channels of communication and social interactions; thus, screen time among children has increased worldwide,” the researchers noted.    

“With the rapid increase in device usage, it is necessary to review the health effects of screen time on infants and to control excessive screen time,” they urged.

Participants in the cohort study were 84,030 mother-child dyads. Mothers were asked to report on screen time of their children at 1 year of age using a questionnaire. Children were followed up on development of ASD based on mother’s response to the items in the Ages and Stages Questionnaire (ASQ-3). [JAMA Pediatr 2022;176:384-391]

At 3 years of age, 0.4 percent of the children had ASD (prevalence of 392 per 100,000), with incidence being threefold higher in boys than girls (76 percent vs 24 percent). 

Compared with children not exposed to screens, those who spent longer hours looking at screens were increasingly more likely to have ASD, with the risk peaking for those with screen time of 2 to <4 hours a day (odds ratio [OR], 1.38; p=0.35 for <1 hour; OR, 2.16; p=0.02 for 1 to <2 hours; OR, 3.48; p<0.001 for 2 to <4 hours; and OR, 3.02; p=0.04 for >4 hours of screen time per day).    

While factors such as maternal nurturing attitudes and abuse have been suggested to influence children’s screen time, the association between longer screen time and ASD in boys remained “irrespective of potential maternal maltreatment or children’s predisposition to ASD at 1 year of age” after adjustment in logistic regression analysis.

Meanwhile, there was no association between screen time and risk of ASD among girls.

Based on the World Health Organization (WHO) 2019 guidelines for children under age 5, exposure to screens should be avoided in children aged ≤1 year. The American Academy of Pediatrics (AAP) holds similar position, recommending that “children should not be exposed to screens until they are 18 months of age.” There have also been warnings about the detrimental effects of screen exposure on children’s health and well-being.

“Despite the WHO and the AAP recommendations, 90 percent of the children in this study had been exposed to screens at 1 year of age,” the researchers pointed out.

As children were still in a developmental stage at 3 years of age, mild cases of ASD might have been under detected at this stage, and the findings might be biased toward severe ASD cases, according to the researchers.