Early Childhood Reading for Pleasure: Evidence from the ABCD Study for Benefits to Cognitive Performance and Mental Health and Associated Changes in Brain Structure

BACKGROUNDEarly childhood has increasingly been recognized as an important neurodevelopmental period. However, the links between specific forms of early educational activities and cognition and mental health remain unclear. METHODSA large-scale analysis on the attainments of childhood Reading for Pleasure (early RfP) and its relationship with young adolescent measures of cognition, mental health and brain structure was conducted, using linear mixed-effects model, structural equation and mediation analyses. Participants were from the Adolescent Brain and Cognitive Development (ABCD) study, a USA national cohort (n=11,878). A two-sample Mendelian randomization (MR) analysis using genetic instruments from two independent genome-wide association studies (GWAS) based on ABCD and GWAS meta-analyses including UK-biobank datasets were conducted to assess potential causal inference. RESULTSEarly RfP was positively associated with cognitive assessments, which in contrast, was negatively associated with dimensional psychiatric problems in young adolescents. MR analysis revealed a beneficial relationship between early RfP and later-life cognitive performance, and a trend towards a protective relationship between early RfP and later-life attention disorder. Brain regions in which larger cortical areas were positively associated with early RfP included the superior temporal, prefrontal, left angular, parahippocampal, right anterior cingulate (ACC), occipital, supramarginal and orbital regions and subcortical ventral diencephalon (DC), thalamus, and brainstem volumes. Mediation analysis indicated that the brain regions significantly mediated the effects of early RfP with better cognitive performance and lower psychiatric problems. INTERPRETATIONOur results highlight the importance of encouraging RfP in young children during the critical early childhood stage, as it was associated with beneficial outcomes for cognition, mental health, and brain structure later in life.