Sleep as a potential link between exposome, mental health and cognitive development in children and adolescents - a scoping review

BACKGROUND: Children's and adolescents' mental health and cognitive development are shaped by complex environmental exposures across their life-course. The exposome framework provides an integrative approach to assess the interlinkages. While sleep is a prerequisite for mental and cognitive health, its role as an underlying pathway remains unclear. This review aims to map and contextualize the evidence on whether sleep mediates or moderates associations between the exposome and mental health, well-being, or cognitive outcomes in individuals aged 0-21 years. METHODS: Following PRISMA-ScR guidelines, we conducted a scoping review of peer-reviewed studies published in English from 2000 to January 2025. Scopus and PsycINFO were searched, supplemented by reference screening and cohort-based searches. Two reviewers independently screened records and charted data, which were synthesised narratively. RESULTS: Twelve studies examined the full causal chain from multiple environmental exposures to mental health or cognitive outcomes via sleep, with 34 additional studies addressing specific partial pathways. Most studies were cross-sectional and conducted in high-income countries. Sleep was primarily assessed using self- or parent-reported measures. Evidence suggested that sleep may mediate or moderate associations between the exposome and mental health or cognitive outcomes, however, longitudinal evidence remains notably limited. The diversity of exposures and domains points to the effect being a result of multiple exposures emphasising the importance of an exposome perspective within early life exposures and outcomes. CONCLUSIONS: Sleep represents an important pathway linking the exposome to mental health and cognitive development, however longitudinal, child-centred exposome research remains scarce.