To the Editor Kushima et al1 found that longer screen time at age 1 year was significantly associated with autism spectrum disorder (ASD) at age 3 years among boys in Japan. In the Discussion, the authors only described the electromagnetic field as one of the possible mechanisms of screen exposure affecting the risk of ASD. We suggest that the investigation of presleep screen time might strengthen the authors’ findings and clarify the possible mechanisms for evidence-based intervention.
