Associations among socioeconomic disadvantage, longitudinal changes in within-network connectivity, and academic outcomes in the ABCD study.

Lower parental socioeconomic status (SES) is consistently linked to lower academic achievement among adolescents, with early disparities persisting into adulthood. However, the neurobiological mechanisms underlying these associations are not well understood. This preregistered study investigates the associations between household and neighborhood disadvantage-measured by income-to-needs ratio, parental educational attainment, and neighborhood SES-changes in within-network functional connectivity, and school grades, using longitudinal data from the Adolescent Brain Cognitive Development Study (N = 4745; age at baseline = 119.1 ± 7.5 months; age at 2-year follow up = 143.6 ± 7.8 months; age at 3-year follow up = 154.8 ± 7.7 months). Within-network connectivity changed significantly from baseline to follow-up, increasing in most networks (e.g., default mode, fronto-parietal) and decreasing in a few (e.g., salience, ventral attention). After controlling for other SES indicators, parental education and neighborhood disadvantage, but not income, were associated with changes in connectivity across several brain networks, including reduced increases in default mode, cingulo-opercular, and visual network connectivity and greater increases in within-sensorimotor network connectivity. Further, changes in sensorimotor connectivity mediated the relationship between parental educational attainment and academic achievement three years later. These findings highlight the importance of parental education and neighborhood environments in shaping neurodevelopmental trajectories that influence academic outcomes. Understanding the mechanisms that link socioeconomic disadvantage with academic outcomes could inform interventions aimed at reducing persistent achievement gaps.