Screen time of 2-3 hours at one year of age predisposes boys to autism spectrum disorder at 3 years of age, according to a multicenter Japanese study reported in JAMA Pediatrics.¹

Researchers investigated the association of screen time at one year of age with development of autism spectrum disorder at 3 years of age. For this they examined data obtained from the Japan Environment and Children’s Study. A total of 84,030 mother-child pairs, between January 2011 and March 2014, were included in the analysis.

The screen time was assessed at 1 year of age and also at 3 years of age with the help of a questionnaire wherein the mothers were asked about how many hours their child watches TV or DVDs ranging from less than one hour to 4 hours or longer. The commonest answer to this was less than 1 hour of screen time per day. At 3 years of age, the mothers were asked if their child had been “diagnosed with autism spectrum disorder (e.g., autism, pervasive developmental disorder, Asperger’s syndrome) by a doctor from the age of 2 years until now?” and the answers were noted as yes or no.

Results showed that the 330 children (0.4%) developed autism spectrum disorder at 3 years of age. Of these, 79 (24%) were girls and 251 (76%) were boys. ASD was diagnosed in nearly 6% of children with no screen time, 22.3% with less than one hour screen time, 30.2% with screen time of 1 to less than 2 hours were diagnosed with ASD; ~32% with 2 to less than 4 hours and 10% with 4 hours or more of daily screen time

Compared to girls, boys were thrice more likely to develop autism spectrum disorder and the association was stronger as the number of hours of screen time increased. The adjusted odds ratio was 1.38 for screen time of less than one hour, 2.16 for one hour to less than 2 hours, 3.48 for 2 hours to less than 4 hours and 3.02 for ≥ 4 hours. No such association between autism spectrum disorder and screen time was noted for girls.

This study has demonstrated a significant association of longer screen time at one year of age with development of autism spectrum disorder at 3 years of age among boys. Given the way devices like smartphones have become an integral part of our day-to-day life, it becomes imperative to examine the impact of screen time on infants and to strictly regulate screen time. The WHO recommends no screen time for children younger than one year of age, while the American Academy of Pediatrics (AAP) increases the age to 18 months for no screen time.

Reference

1. Kushima M, et al; Japan Environment and Children’s Study Group. 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 Childrens Study. JAMA Pediatr. 2022 Apr 1;176(4):384-391. doi: 10.1001/jamapediatrics.2021.5778.