In the February issue of the American Journal of Psychiatry, researchers Nathalie M. Durmonay, Lauren AM Lebois, Kerry J. Ressler, and Nathaniel G. Harnett published their findings on the correlation between childhood adversity experienced disproportionately by black children in the US and differences in in neurological development.
Evaluating research from the Adolescent Brain Cognitive Development study, US Census neighborhood data, and MRI scans of 1,786 black and 7,350 white children ages nine to 10, the team found small variations in gray matter volume in brain regions related to stress.
Hannett said in an interview Tuesday that the findings of this study stand in stark contrast to the myth that there are inherent neurological differences between people of different races.
“One of those folk beliefs is that black individuals have smaller brains than white people,” Harnett said. “What our results really show is that a significant part of the differences between groups can actually be attributed to adversities that these groups may experience differently during childhood.”
The study suggests that a major contributor to the disparity in gray matter volume between black and white children is the disproportionate adversity experienced by black children. The researchers found that structural racism — including the likelihood of experiencing poverty, traumatic events and family conflict — can affect the differential development of the amygdala, hippocampus and prefrontal cortex.
In addition to supporting this relationship, the study has implications for future research on the relationship between experienced adversity and post-traumatic stress disorder. When analyzing previous PTSD research in conjunction with this study, researchers noted that black children had greater severity of PTSD symptoms, and “symptom severity was predicted by adversity,” according to the study.
“I want to understand why some people end up with PTSD,” Harnett said. “I think the brain is probably the best way to understand this and predict who is likely to develop it.”
This research has practical implications for clinicians seeking to better understand their patients’ backgrounds.
“If we want to understand where our patients are going to end up and how they’re going to do, we really need to understand what’s been going on in the past and how, for different patients and different individuals, these different experiences can contribute to different outcomes,” Harnett said.
In the future, this group hopes to observe the same relationship in other age groups.
“The main focus for us going forward is that we really want to know, ‘What does the developmental trajectory look like for individuals who are experiencing more adverse childhood events?’” he said.
Harnett hopes this will help people think about how structural racism affects future generations.
“We really hope these findings motivate people to really consider widespread structural changes to address systemic inequalities, to address the traumas that people can experience in childhood,” he said.