Associations Between Screen Time, Sleep, and Executive Function in School-Aged Children and Adolescents: The Moderating Role of Digital Content and Age

<b>Background and Objectives</b>: Increased and unstructured digital exposure has raised growing concerns about its potential impact on children's cognitive and behavioral development. Executive functions (EFs)-encompassing attention, working memory, inhibition, and cognitive flexibility-are particularly sensitive to environmental influences during development. Beyond its empirical aim, this study also sought to address a theoretical gap by clarifying how multiple dimensions of digital exposure (quantity, content quality, and sleep-related timing) jointly relate to EF performance, an area insufficiently integrated into current EF frameworks. This study aimed to examine the quantitative and qualitative dimensions of digital exposure in relation to sleep duration and EF performance among Romanian school-aged children and adolescents. <b>Materials and Methods</b>: A cross-sectional study was conducted among 142 students aged 5-19 years, using standardized cognitive tasks and structured parent questionnaires to assess screen time, digital content type, and sleep duration. Analyses included correlational tests, group comparisons, regression models, and moderation procedures. <b>Results</b>: Higher daily screen time was associated with poorer attention and working-memory performance and shorter nocturnal sleep. Children and adolescents who exceeded the recommended daily screen-time limits performed worse on executive-function measures than those within recommended limits. Digital content type and sleep duration each contributed uniquely to executive performance, and recreational digital content as well as younger age intensified the negative effects of screen exposure. <b>Conclusions</b>: Excessive daily screen time, especially involving passive or recreational content, is associated with poorer EF performance and shorter sleep in children. Adequate sleep and educational or interactive digital engagement may mitigate these effects. The findings underscore the importance of age-appropriate, structured, and balanced digital habits to support healthy cognitive development.