Structural inequities contribute to racial/ethnic differences in neurophysiological tone, but not threat reactivity, after trauma exposure

Molecular Psychiatry, 2023 · DOI: https://doi.org/10.1038/s41380-023-01971-x · Published: February 1, 2023

Simple Explanation

This study investigated racial and ethnic differences in brain activity and physiological responses after trauma exposure, focusing on the amygdala's role in PTSD. The researchers found that Black individuals had lower baseline physiological arousal but greater amygdala connectivity compared to White individuals. These differences in brain connectivity were linked to later PTSD symptoms, and structural inequities partly explained these racial/ethnic variations.

Study Duration

Not specified

Participants

n = 283, trauma-exposed participants

Evidence Level

Not specified

Key Findings

1
Black participants showed lower tonic skin conductance levels and startle compared to White participants, but no differences were observed in physiological reactions to threat.
2
Hispanic and Black participants showed greater amygdala connectivity to regions including the dorsolateral prefrontal cortex (PFC), dorsal anterior cingulate cortex, insula, and cerebellum compared to White participants.
3
Amygdala connectivity was associated with 3-month PTSD symptoms, but the associations differed by racial/ethnic group and were partly driven by group differences in structural inequities.

Research Summary

The study examined racial/ethnic differences in neurophysiological reactivity and connectivity following trauma exposure using fMRI and psychophysiology. Findings revealed that Black and Hispanic individuals displayed heightened amygdala connectivity with salience network nodes compared to White individuals; Black participants also exhibited lower tonic physiological arousal. Structural inequities partially accounted for observed racial/ethnic differences in amygdala connectivity and baseline startle responses, suggesting their role in shaping neural responses to trauma.

Practical Implications

Targeted Interventions

Consideration of racial/ethnic variability in neural connectivity after trauma is crucial for equitable neuroscience-based treatment outcomes.

Understanding PTSD Development

The findings contribute to understanding how structural inequities influence neural processes mediating susceptibility to later PTSD symptoms.

Neuromodulatory Treatment Considerations

The study highlights the potential impact of early life stressors on the generalizability of neuromodulatory targets for different racial/ethnic groups.

Study Limitations

1
Sample limited to Hispanic, non-Hispanic White, and non-Hispanic Black participants.
2
Socioeconomic factors assessed may not fully capture structural inequities.
3
Physiological and rs-fMRI data were not collected concurrently.

Your Feedback

Was this summary helpful?

Back to Mental Health