Social safety nets may blunt effects of poverty on children’s mental health

The study suggests that social safety nets can help improve children’s brain development and mental health. Pressmaster / Shutterstock

Family income is associated with differences in children’s brain development and mental health. This can, in turn, affect later-life outcomes. But it isn’t known how broader social factors, such as the cost of living and the social safety net, can affect the strength of these associations.

An NIH-funded research team, led by Dr. David Weissman at Harvard University, examined how these differences in children’s brain development and mental health vary across states with different costs of living and anti-poverty programs. To do so, they analyzed data on more than 10,000 children, ages 9-11, from 17 states in the Adolescent Brain Cognitive Development (ABCD) study.

The team looked at two features in children known to correlate with income. One is the volume of the hippocampus—a part of the brain involved in memory processing. The other is internalizing and externalizing symptoms, which were assessed by analyzing parents’ responses about their children’s behavior. These symptoms, when severe, have been associated with anxiety, mood, and behavioral disorders.

The researchers measured the benefits from states’ social safety nets in two different ways. One was the average monthly benefits from two large cash assistance programs: the Earned Income Tax Credit and Temporary Assistance to Needy Families. The other was whether a state opted to expand Medicaid eligibility under the Affordable Care Act. Their results appeared in Nature Communications on May 2, 2023.

The team found that lower income was associated with a smaller hippocampus and increased internalizing symptoms. This agreed with previous studies. The differences between participants from high- or low-income households, however, varied across states. These differences tended to be larger in states with a higher cost of living. But among high cost-of-living states, the differences were smaller in those that offered more cash benefits. The difference in hippocampal volume between participants from high- and low-income households was 34% lower in high cost of living states with high cash benefits versus low cash benefits. The difference in internalizing symptoms was 48% lower.

Differences with income in both hippocampal volume and internalizing symptoms also varied with Medicaid expansion. Among high-cost states, the disparity in hippocampal volume was 43% smaller in states that expanded Medicaid than in those that didn’t. The difference in internalizing symptoms was also smaller in high-cost states that expanded Medicaid.

This analysis suggests that the effects of a stronger social safety net may offset the effects of cost of living on disparities in children’s brain development and mental health. Disparities in high-cost states with a stronger social safety net resembled those in the lowest-cost states. These effects held even when controlling for various state-level social, economic, and political factors such as population density, economic inequality, political preferences, and educational equity.

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

The researchers caution that their study was observational in nature. Thus, it can’t definitively show that other factors aren't influencing the disparities that they studied. Future experimental studies would be needed to assess the impact of specific policies on such disparities.