Neurobiological and Cognitive Mechanisms of Attention Deficit Hyperactivity Disorder (ADHD) Risk Associated with Screen Exposure in Preschool Children: Literature Review

Abstract

The preschool period is a critical stage of neurodevelopment, marked by rapid brain maturation and the development of executive functions. In the digital era, excessive screen exposure has raised concerns regarding its potential association with attention deficit hyperactivity disorder (ADHD). This literature review synthesizes evidence on the neurobiological, cognitive, and motor mechanisms linking screen time to ADHD risk in early childhood. Peer-reviewed studies published from 2017–2026 were identified through PubMed, ScienceDirect, and Google Scholar. Evidence suggests a dose-response relationship, with screen exposure exceeding 1 hour per day associated with increased ADHD symptoms. Rapid-paced media may overstimulate attention pathways and affect prefrontal and dopaminergic function, while bedtime screen use may disrupt sleep through melatonin suppression. Additionally, sedentary screen time can reduce physical activity and potentially affect motor development. Therefore, supervised limitation of screen time to a maximum of 1 hour per day may support healthy neurodevelopment during early childhood.