(The Hill) — Children in poverty tend to have healthier brains and fewer mental health problems if they live in states with more generous welfare programs, according to a new study supported by the National Institutes of Health. 

The findings, from researchers at Harvard and Washington University in St. Louis, suggest that well-funded anti-poverty measures can improve both brain development and mental health in children. 

Past research has shown an association between poverty and brain development. Specifically, children in low-income homes tend to have a smaller hippocampus, a brain structure associated with memory and learning. Impoverished children also suffer more frequent mental health symptoms.  

Across the 17 states studied, impoverished children tended to have a smaller hippocampus than affluent children. But in states with robust welfare programs, the disparity was 34 percent narrower.  

In mental health, the study found the disparity between affluent and impoverished children 48 percent lower in states with comparatively generous welfare programs, such the Earned Income Tax Credit, Temporary Assistance for Needy Families and Medicaid.  

Researchers reviewed data for more than 10,000 children ages 9 to 11, using brain scans to determine the size of the hippocampus in each young subject. The study appears in the journal Nature Communications. 

“The association between brain structure and a low-resource environment is not an inevitability,” said David Weissman, a postdoctoral fellow at Harvard’s Stress and Development Lab and one of the report’s authors. “These data suggest that policies and programs that work to reduce social and health inequalities can directly reach children in disadvantaged environments and help support their mental health.” 

Researchers found the brain benefits of welfare strongest in states with relatively high costs of living: Higher living expenses place greater strain on families living in poverty.  

In states with high living costs and relatively stingy welfare programs, such as Colorado, Pennsylvania, Florida and Virginia, researchers found that children from low-income homes had a smaller hippocampus. In states with high living costs and high cash aid, such as New York, Connecticut and California, the hippocampus was larger among children living in poverty.  

Researchers also found significantly higher rates of mental illness among impoverished children in high-cost states with weaker welfare programs and fewer mental health problems in states with stronger programs. 

The study compared states on several welfare initiatives.  

One is the state-level Earned Income Tax Credit for lower-income households. California and Maryland provide significant tax credits to supplement the federal program. Florida, Missouri and Pennsylvania do not. 

Another local variable is Temporary Assistance to Needy Families, tailored for households struggling to meet basic needs. According to study data, that program delivers more money in California, Connecticut and Maryland, less in Florida, Missouri and Pennsylvania.  

A third factor is Medicaid. Some states have accepted federal funding to expand the federal program, which provides health coverage to low-income adults. Others have not, a decision that reflects lingering political divisions over the Obama-era Affordable Care Act. 

The study found a marked brain benefit in states that accepted expanded Medicaid, including Vermont, California, Oregon and Connecticut, and poorer brain health in states that did not, including Florida and Utah.  

The new research was supported by the National Institute on Drug Abuse (NIDA) at the National Institutes of Health. 

“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 psychological disorders,” said Nora Volkow, director of NIDA. “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.”