Thursday, February 2, 2023

Childhood Adversity May Account for Some Brain Differences Between White, Black Children

Black children are more likely to experience adverse life events than White children, and these disparities may contribute to differences between their brains, according to a study published yesterday in The American Journal of Psychiatry.

“What the data show is the overwhelming impact of structural racism on the developing brain, which is going to have big implications for these kids’ emotional health as they start to get older, especially if we don’t address the different aspects of structural inequities and racism,” Nathaniel Harnett, Ph.D., of McLean Hospital told Psychiatric News.

Harnett and colleagues used data from the Adolescent Brain and Cognitive Development (ABCD) Study released in March 2019, which included 9,382 participants aged 9 and 10. They gathered family demographic data through surveys that the participants’ parents completed. The surveys assessed both parent and child race/ethnicity; parental education and employment; parental hardship (such as not being able to afford rent); and total family income, among other variables.

The participants’ neighborhood disadvantage was assessed using the Area Deprivation Index, which uses 17 socioeconomic indicators—including poverty, housing, and employment—to characterize a given neighborhood. Family conflict was assessed using the Youth Family Environment Scale, and trauma history was assessed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children for DSM-5. The authors used structural MRI data to investigate the relationship between racial disparities in adversity exposure and differences in brain structure.

The authors found that White children’s parents were more likely to be employed, have higher educational attainment, and greater family income compared with Black children’s parents (88.1% of White parents made $35,000 a year or more versus 46.7% of Black parents). White children also experienced less family conflict, less material hardship, less neighborhood disadvantage, and fewer traumatic events compared with Black children.

Childhood adversity was associated with lower gray matter (nodes where information is processed) volume in the amygdala and several regions of the prefrontal cortex. White children showed greater gray matter volume compared with Black children in 10 brain regions. Black children showed lower gray matter volumes in the amygdala, the hippocampus, and several subregions of the prefrontal cortex compared with White children. These regions of the brain are key to regulating the emotional response to threat, Harnett explained, but he emphasized that, overall, these differences were small.

In an accompanying commentary, Deanna Barch, Ph.D., and Joan Luby, M.D., of the Washington University School of Medicine in St. Louis pointed to some of the additional adverse social determinants of health that were not examined in the study, such as a youth’s personal experience of racism. They wrote that some people have argued that the experience of racism is a form of trauma itself that can lead to posttraumatic stress disorder.

The study “is an important step towards understanding how [social determinants of health] impact brain development in youth as a potential pathway to risk for mental health challenges,” Barch and Luby wrote.

For a more coverage of this study, see the Psychiatric News article “Childhood Adversity Impacts Brain Development, Study Shows.

(Image: iStock/Hank Grebe)




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