Neighborhood disadvantage and brain myelination: Insights from infancy to childhood

Early life adversity (ELA), including poverty and socioeconomic disadvantage, can negatively impact neurodevelopment and long-term health outcomes. Here, we examined associations between neighborhood-level disadvantage, indexed by the Area Deprivation Index (ADI), and white matter myelination in infants and children aged 0-10 years (n = 61 MRI acquisitions across 43 children). Quantitative MRI-derived longitudinal relaxation rates (R1) are sensitive to myelin content and were used to assess white matter development. Higher ADI national percentiles (reflecting greater neighborhood disadvantage) were associated with lower R1 in several white matter regions, including the internal capsule, corona radiata, cingulate gyrus, fronto-occipital fasciculus, superior longitudinal fasciculus, and uncinate fasciculus. Whole-brain voxel-wise analyses further supported negative associations between ADI and myelination. These findings were stronger in the infant subsample and implicate white matter pathways supporting cognitive, socioemotional, and motor functions, suggesting that early environmental disadvantage may influence neurodevelopmental trajectories. Future work should examine which components of ADI drive these associations and how resilience may buffer the effects of disadvantage.