Perceived Racism, Brain Development, and Internalizing and Externalizing Symptoms: Findings From the ABCD Study.

OBJECTIVE

Racial discrimination drives health disparities among racial/ethnic minority youth, creating chronic stress that affects brain development and contributes to mental and behavioral health issues. This study analyzed data from the Adolescent Brain Cognitive Development (ABCD) Study to examine the neurobiological mechanisms linking discrimination to mental and behavioral health outcomes.

METHOD

A sample of 3,321 racial/ethnic minority youth was split into training (80%, n = 2,674) and testing (20%, n = 647) groups. Propensity score-weighted machine learning was used to assess the effects of perceived discrimination on 2-year changes in resting-state functional connectivity between 3 subcortical regions (nucleus accumbens, amygdala, and hippocampus) and large-scale brain networks. Mediation analyses evaluated whether brain changes mediated sex-specific effects on internalizing or externalizing symptoms.

RESULTS

Perceived discrimination was significantly associated with 2-year changes in connectivity of the nucleus accumbens, amygdala, and hippocampus in both cross-validation and independent testing. Key findings included decreases in nucleus accumbens connectivity with retrosplenial-temporal and sensorimotor (hand) networks, decreases in amygdala connectivity with the sensorimotor (mouth) network, and increases in hippocampal connectivity with the auditory network. These changes suggest accelerated maturation in these connections among youth reporting higher discrimination levels. Moderated mediation analyses revealed sex differences, with discrimination-related changes in nucleus accumbens connectivity linked to poorer internalizing outcomes in female participants.

CONCLUSION

The results indicate that perceived racial discrimination experienced in adolescence have an impact on subcortical-cortical brain development, which affects mental and behavioral health outcomes in a sex-specific manner.

DIVERSITY & INCLUSION STATEMENT: We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science.