Poverty hurts young brains, but social safety net can help – Harvard Gazette

Time and again, science finds that poverty harms brain development.

“Higher levels of anxiety and depression are well established in children growing up in low-income families,” said the Harvard psychology professor. Katie A. McLaughlin. “Over the past decade, we have learned that there are also differences in brain development depending on the socio-economic status of the family.

But a strong social safety net can protect young minds from these effects, according to a new paper in Nature Communications by McLaughlin and colleagues. Benefits such as cash assistance and access to Medicaid appear to be particularly beneficial for children in states with high living costs.

The researchers relied on Adolescent Brain Cognitive Development (ABCD) Study, which tracks more than 11,000 young people in 17 states. ABCD collects troves of parent-reported behavioral health data and uses neuroimaging to track brain development. “Historically, it’s been quite rare to have what we call multisite neuroimaging studies, where you collect data from people in many different places,” McLaughlin said.

A previous study conducted by Mark L. Hatzenbuehlerassociate professor of social sciences John L. Loeb, used ABCD data to find associations between brain structure and the prevalence of stigma, including racism, sexism, and anti-immigration attitudes in various states.

“These are really the first studies able to examine how broader aspects of the social and economic environment affect brain development,” McLaughlin said, noting that Hatzenbuehler is a co-author on the new paper. “We think they open up a whole new set of research questions that we call ‘contextual cognitive neuroscience’.”

Previous research has established that children who grow up in low-income households “tend to have smaller hippocampal volume,” says David Weismannlead author of new paper and postdoctoral fellow at McLaughlin’s Stress and Development Lab. The hippocampus is central to memory and learning, Weissman added, but it’s also susceptible to chronic stress. Animal studies show that constantly elevated stress hormones such as cortisol can reduce the formation of synapses (or connections between neurons) in this region of the brain.

That’s important because a smaller hippocampus is a predictor of poor academic performance, McLaughlin said. “There is also fairly consistent evidence that children with smaller hippocampal volume may be more vulnerable to the development of mental health problems, particularly during adolescence.”

Consistent with previous research, Weissman and his team found lower hippocampal volume in 10- and 11-year-old ABCD participants from low-income families. Higher rates of mental health problems, including anxiety and depression, have also been documented in this population.

The greatest disparities between children from low-income and high-income families have been observed in states with high living costs.

“But interestingly, we see it’s not an inevitable outcome,” McLaughlin said. In fact, generous social spending appears to be narrowing the gap between children from high-income and low-income families in expensive states like California and New York. “What we’re seeing is that the disparity is similar to much cheaper states,” McLaughlin said. “The magnitude of disparities in brain structure is reduced by about a third, while disparities in mental health are reduced by nearly half.”

The researchers looked at the impacts of three government programs: the state and federal income tax credit, temporary assistance for needy families, and the expansion of Medicaid under the Affordable Care Act. Program generosity varies by state, which is easy to track with plenty of public data.

As Weissman pointed out, the researchers were even able to identify ABCD families eligible for public assistance. They also identified participants from households with incomes just above the eligibility threshold. “We found that the impact of anti-poverty programs was specific to those who actually benefited from them,” he said.

Additional testing found reduced disparities in states with higher minimum wages. “We use these specific policies to test our research questions,” McLaughlin noted, “but we really think they are just indicators of a much larger set of social safety net policies that cover many areas. of life.”

In the future, Weissman hopes to exploit ABCD data for what he calls “natural experiments.” That is to say, he wants to monitor the deployment of new anti-poverty policies.

As an example, McLaughlin cited the various US cities — including Los Angeles and several others in California — that are piloting universal basic income programs. If any of the ABCD states implemented such a policy, she said, “it would allow us to examine whether there is a reduction in socioeconomic disparities in children’s brain structure and mental health. “.