Antipoverty programs mitigate socioeconomic disparities in hippocampal volume and internalizing problems among U.S. youths

Can public policies that increase financial resources for families with low income reduce socioeconomic disparities in brain development and mental health? We leverage the Adolescent Brain and Cognitive Development (ABCD) study of over 10,000 youth across 17 states to answer this question. Lower income was associated with smaller hippocampal volume and higher internalizing psychopathology. These associations were stronger in states with higher cost of living. However, in high cost-of-living states with larger cash benefits for lower-income families, socioeconomic disparities in hippocampal volume were reduced by 36%, such that the association of family income with hippocampal volume resembled that in the lowest cost-of-living states. We observed similar patterns for internalizing psychopathology. These patterns were robust to controls for a wide range of state-level social, economic, and political characteristics. These findings suggest that anti-poverty policies may exert a buffering effect against the negative neurodevelopmental and mental health consequences of low income.