Poverty Harms Kids’ Brains but Social Safety Net Appears to Help

Studies have shown that poverty affects children’s brain development and mental health, with long-lasting effects, the National Institute of Health (NIH) reports. Children growing up in socio-economically disadvantaged households show changes in the brain. What has been less clear is whether social factors – such as the existence of a social safety net – can mitigate those differences in brain development.

To that end, NIH funded a research team led by Dr. David Weissman of Harvard University to examine “differences in children’s brain development and mental health vary across states with different costs of living and anti-poverty programs.” Their Adolescent Brain Cognitive Development (ABCD) study analyzed data on over 10,000 children, ages 9-11, from seventeen states across the country.

Their focus was twofold. First, they looked at the volume of the brain’s hippocampus, the region involved in memory processing. Second, they explored the degree to which children display internalizing or externalizing symptoms – which are associated with anxiety, mood, and behavioral disorders. In the case of internalizing symptoms (sadness, depression, anxiety, loneliness), an individual directs problems inward, as opposed to outward in externalizing symptoms, such as aggression, conduct disorders, or substance abuse.

The researchers then examined the benefits of various states’ social safety nets in two different ways: 1) cash assistance programs like the Earned Income Tax Credit and Temporary Assistance to Needy Families, and 2) whether a state opted to expand Medicaid eligibility under the Affordable Care Act, making health insurance possible for a greater number of lower-income families. Their findings were published in Nature Communications on May 2, 2023.

The study discovered that “lower income was associated with a smaller hippocampus and increased internalizing symptoms,” findings in line with previous studies. However, the differences between participants from high- or low-income households differed from state to state. In states with a high cost of living, those brain and symptom differences tended to be more pronounced.

However, in states who adopted social safety net programs, those differences were significantly reduced. In high-cost-of-living states providing high cash benefits, the difference in hippocampal volume in children’s brains was 34% lower than in states who provided little financial assistance. And the difference in internalizing symptoms like depression and anxiety was 48% lower.

Medicaid expansion seemed to have similar effects: “Among high-cost states, the disparity in hippocampal volume was 43% smaller in states that expanded Medicaid than in those that didn’t” and internalizing symptoms were also reduced.

“The association between brain structure and a low-resource environment is not an inevitability,” says Weissman. “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.”

To learn more, read the full article or the published research.