Although nearly 90% of Americans will experience trauma, our understanding of factors that contribute to the risk of developing PTSD is still limited. Historically, approaches to understanding PTSD have focused largely on individual factors (e.g., coping strategies, gender) and ignored contextual factors that may influence an individual’s mental health.
Through a renewed lens, the broader context in which trauma survivors reside has emerged as a critical factor in understanding pre-trauma vulnerability.
Where you live influences the likelihood of experiencing trauma and your experiences during the healing process.
My master’s thesis provided preliminary evidence that neighborhood socioeconomic disadvantage and lower individual socioeconomic position are associated with smaller brain regions (ventromedial prefrontal cortex and hippocampus) and aberrations in resting-state functional connectivity of the amygdala and insula (Webb et al., 2021). These results suggest that neighborhood disadvantage is a form of chronic stress, over and above individual-level stressors and acute trauma exposure.
My dissertation investigated whether protective factors, including social support and racial-ethnic identity, buffered against the effects of neighborhood disadvantage and income on neurobiology and if these relationships varied between ethnoracial groups.
We found that neighborhood disadvantage was significantly related to white matter tract integrity (Webb et al., under review). Specifically, greater ADI was associated with lesser integrity in the forceps’ major tract, which supports interhemispheric integration of visual information, and greater integrity of the cingulum-cingulate gyrus, a tract that underlies neural communication between emotion regulation regions. Previous work has suggested that emotion regulation abilities are most beneficial to individuals who experience economic hardship. Therefore, the altered integrity may reflect the importance of effective communication between these regions for those living in more disadvantaged neighborhoods.
In the second chapter, I investigated the effects of both neighborhood disadvantage and racial-ethnic identity on resting-state functional connectivity of the anterior cingulate cortex (ACC) which is involved in emotion regulation processes. I found that lower income – but not neighborhood disadvantage – was significantly associated with greater connectivity between the ACC and visual regions.
For ethnoracially minoritized individuals, racial-ethnic identity buffered the effects of income on ACC connectivity. These results demonstrated a neurobiological mechanism by which racial-ethnic identity may buffer against socioeconomic disadvantage and suggests that racial-ethnic identity may be a resilience factor that helps protect against some of the negative effects of trauma.
Kate Webb, PhD 