Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, Mass. (Dumornay, Lebois, Ressler, Harnett); Department of Psychiatry, Harvard Medical School, Boston (Lebois, Ressler, Harnett).
Am J Psychiatry. 2023 Feb 1;180(2):127-138. doi: 10.1176/appi.ajp.21090961.
Black Americans in the United States are disproportionately exposed to childhood adversity compared with White Americans. Such disparities may contribute to race-related differences in brain structures involved in regulating the emotional response to stress, such as the amygdala, hippocampus, and prefrontal cortex (PFC). The authors investigated neuroanatomical consequences of racial disparities in adversity.
The sample included 7,350 White American and 1,786 Black American children (ages 9-10) from the Adolescent Brain Cognitive Development Study (public data release 2.0). Structural MRI data, parent and child self-reports of adversity-related measures, and U.S. Census neighborhood data were used to investigate the relationship between racial disparities in adversity exposure and race-related differences in brain structure.
Black children experienced more traumatic events, family conflict, and material hardship on average compared with White children, and their parents or caregivers had lower educational attainment, lower income, and more unemployment compared with those of White children. Black children showed lower amygdala, hippocampus, and PFC gray matter volumes compared with White children. The volumes of the PFC and amygdala, but not the hippocampus, also varied with metrics of childhood adversity, with income being the most common predictor of brain volume differences. Accounting for differences in childhood adversity attenuated the magnitude of some race-related differences in gray matter volume.
The results suggest that disparities in childhood adversity contribute to race-related differences in gray matter volume in key brain regions associated with threat-related processes. Structural alterations of these regions are linked to cognitive-affective dysfunction observed in disorders such as posttraumatic stress disorder. More granular assessments of structural inequities across racial/ethnic identities are needed for a thorough understanding of their impact on the brain. Together, the present findings may provide insight into potential systemic contributors to disparate rates of psychiatric disease among Black and White individuals in the United States.
与美国白人相比，美国黑人儿童在童年期遭受逆境的比例不成比例。这些差异可能导致与种族相关的大脑结构差异，这些差异与调节对压力的情绪反应有关，如杏仁核、海马体和前额叶皮层（PFC）。作者研究了逆境中种族差异的神经解剖学后果。
该样本包括来自青少年大脑认知发展研究（公共数据发布 2.0）的 7350 名美国白人和 1786 名美国黑人儿童（年龄为 9-10 岁）。结构磁共振成像数据、父母和儿童自身逆境相关措施报告以及美国人口普查社区数据用于研究逆境暴露中的种族差异与大脑结构中的种族差异之间的关系。
与白人儿童相比，黑人儿童平均经历了更多的创伤事件、家庭冲突和物质困难，他们的父母或照顾者的受教育程度、收入和失业人数均低于白人儿童。与白人儿童相比，黑人儿童的杏仁核、海马体和 PFC 灰质体积较小。PFC 和杏仁核的体积（而不是海马体）也随着儿童期逆境的指标而变化，收入是大脑体积差异的最常见预测因素。考虑到童年逆境的差异，减弱了一些与种族相关的灰质体积差异的程度。
研究结果表明，童年逆境的差异导致与威胁相关过程相关的关键大脑区域的种族相关灰质体积差异。这些区域的结构改变与创伤后应激障碍等疾病中观察到的认知情感功能障碍有关。需要更细致地评估种族/族裔身份的结构不平等，以全面了解其对大脑的影响。总之，本研究结果可能为理解美国黑人和白人个体中精神疾病发生率差异的潜在系统性因素提供了新的见解。
