In U.S. states that provide financial assistance for low-income families, the difference is evident in children’s brains, researchers report.

Their study found disparities in brain structure between children from high-income households compared to low-income households. However, the disparity was more than a third lower in states offering greater cash assistance to low-income families, compared to states offering less help.

In addition, the disparity in mental health symptoms was reduced by nearly a half.

The study, which was funded by the U.S. National Institute on Drug Abuse (NIDA), involved more than 10,000 children ages 9 to 11, using data from the Adolescent Brain Cognitive Development Study (ABCD) study.

“The association between brain structure and a low-resource environment is not an inevitability,” said study author David Weissman, a postdoctoral fellow in the Stress and Development Lab at Harvard University.

“Children’s brains are undergoing substantial development and have enhanced plasticity or capacity for further change based on their environment,” Weissman said in a NIDA news release. “These data suggest that policies and programs that work to reduce social and health inequities can directly reach children in disadvantaged environments and help support their mental health.”

Emerging evidence has shown that children from families with lower income have smaller hippocampal volume than those in families with higher income, the researchers said. The hippocampus is involved in both memory and emotional learning.

“Multiple studies have found associations between the brain changes shown in this research and meaningful impacts such as low test scores, lack of school readiness, and risk factors for mood disorders,” NIDA Director Dr. Nora Volkow, said in the release. “Investigating the policy factors that are associated with brain development and mental health is an important part of better understanding health inequities that impact people throughout their lives, starting in critical periods of development.”

The investigators first validated that lower family income is associated with smaller hippocampal volume and more symptoms of mental health conditions like anxiety, depression, aggression, impulsivity and inattention in children.

They expected these differences to be greater in states that cost more to live in, and they were.

Yet, having monetary assistance programs in higher cost-of-living states reduced this disparity by 34%, the study found. States with Medicaid expansion had disparity reduced by 43%.

In states with high cost of living and also anti-poverty programs, gaps were narrower. Similar levels were seen in states with the lowest cost of living.

The study also revealed that the income-associated disparity in some mental health symptoms like anxiety and depression was 48% lower in expensive states with larger cash benefits than in states with lower cash benefits.

The authors noted that these patterns remained significant when controlling for state-level social, economic and political characteristics. These include population density, education equity, incarceration rates and gender equity.

The research demonstrates that this gap can be remedied with state anti-poverty programs, such as Earned Income Tax Credit, Temporary Assistance for Needy Families and Medicaid, according to the researchers.

The study was published May 2 in the journal Nature Communications.

More information

The U.S. Centers for Disease Control and Prevention has more on children’s brain development.

SOURCE: U.S. National Institute on Drug Abuse, news release, May 2, 2023

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