MRIs show stress from poverty, racism may alter brain development of Black children, study says

Black children living in poverty face increased instances of stress and trauma that can alter their brain development, a new study found.

The study was published this week by the American Journal of Psychiatry. Researchers at Harvard University examined MRI scans of 7,350 white and 1,786 Black children ages 9 and 10. The data in the study was collected by the National Institutes of Health in 2019.

Researchers found that increased stressors like economic hardship and systemic racism play a significant role for Black children and can lead to the development of mental health issues as they age, the study said.

The stressors contribute to Black children having less gray matter in their brains, a byproduct of absorbing "toxic stress." The study defines the stressors as "prolonged exposure to adverse experiences" that lead to excessive stress hormones and "disrupt the immune and metabolic regulatory systems."

In the study, researchers found that Black children often developed behavioral problems later in life such as PTSD, anxiety and depression. These children also were susceptible to drug and alcohol abuse and suicide attempts and were likely to commit violence, the study said.

Nathaniel Harnett, an assistant professor of psychiatry at Harvard Medical School who led the study, told CNN their analysis sought to examine how early the effects of structural inequities and racism would appear in brain development. Harnett said his team began exploring a cognitive development study to dispel "this kind of folk belief that Black and White people have categorically different brains."

Harnett said the data researchers examined suggested "that what's really driving any differences are the sort of disproportionate burden of life experiences that people have."

Researchers said Black children are much more likely to be exposed to violence, live in disadvantaged neighborhoods, and combat systemic racism daily than White children. They also are exposed to those factors at an earlier age, the study said.

The most recent US Census data shows that Black families have a lower median income, higher rates of unemployment and poverty, and lower rates of educational achievement compared to White families, the study notes.

Harnett said his team's analysis underscores the need for "large-scale structural and systemic change," especially in policy.

"The adversity that these kids are exposed to, it impacts everyone, but it disproportionately burdens Black children in this case," he said.

Information from CNN was used in this article.