Protect Your Child from Digital Threat: A Comprehensive Medical Reference for Researchers and Clinicians

The rapid proliferation of digital technologies has fundamentally transformed the early childhood environment, giving rise to unprecedented levels of screen exposure among infants, toddlers, and preschoolers. The neurological and developmental consequences of such exposure during the most critical period of brain development remain a subject of intense scientific and clinical debate. Despite growing evidence on early screen exposure, a clear causal understanding of its associations with key developmental domains and the role of moderating and protective factors remains limited. This narrative review synthesises evidence published between 2000 and 2026 on the associations between screen time and multiple domains of early childhood neurodevelopment, including language acquisition, cognitive functioning, executive function, social-emotional competence, attentional capacity, and sleep architecture. The review further explores underlying biological and experiential mechanisms, evaluates the role of moderating variables such as content type, interactivity, and parental co-engagement, and critically appraises current evidence-based guidelines from major paediatric and public health organisations. Converging evidence indicates that excessive passive screen exposure in the first five years of life is consistently associated with delays in expressive and receptive language, attentional deficits, reduced executive function capacity, sleep disturbances, and heightened internalising and externalising behavioural problems. Neuroimaging studies have begun to reveal structural brain correlates of heavy screen use, particularly alterations in white matter integrity in regions underpinning language and literacy. Nonetheless, methodological heterogeneity, reliance on parental self-report, and the rapid pace of technological change complicate definitive causal inference. Interactive, high-quality, co-viewed content appears to carry fewer developmental risks than passive, rapid-paced, or background exposure. Major paediatric bodies recommend no screen time for children under 18–24 months (except for video-chatting) and strict limits on duration and content for older preschoolers. Clinicians have a pivotal role in screening for excessive screen use, providing anticipatory guidance, and supporting families in adopting evidence-based media practices. Future research should prioritise longitudinal and neuroimaging-based studies using objective measures of screen exposure to elucidate causal relationships and better understand how early screen use influences brain structure, connectivity, and functional development in young children.