Discrimination Exposure, Neural Reactivity to Stress, and Psychological Distress.

Abstract

Objective: Discrimination exposure has a detrimental impact on mental health, increasing the risk of depression, anxiety, and posttraumatic stress. The impact discrimination exposure has on mental health is likely mediated by neural processes associated with emotion expression and regulation. However, the specific neural processes that mediate the relationship between discrimination exposure and mental health remain to be determined. The present study investigated the relationship adolescent discrimination exposure has with stress-elicited brain activity and mental health symptoms in young adulthood.

Methods: A total of 301 participants completed the Montreal Imaging Stress Task while functional MRI data were collected. Discrimination exposure was measured four times from ages 11 to 19, and stress-elicited brain activity and psychological distress (depression, anxiety, posttraumatic stress) were assessed in young adulthood (age 20).

Results: Stress-elicited dorsolateral and dorsomedial prefrontal cortex (PFC), inferior parietal lobule (IPL), and hippocampal activity varied with discrimination exposure. Activity within these brain regions varied with the cumulative amount and trajectory of discrimination exposure across adolescence (initial exposure, change in exposure, and acceleration of exposure). Depression, anxiety, and posttraumatic stress symptoms varied with discrimination exposure. Stress-elicited activity within the dorsolateral PFC and the IPL statistically mediated the relationship between discrimination exposure and psychological distress.

Conclusions: The findings suggest that adolescent discrimination exposure may alter the neural response to future stressors (i.e., within regions associated with emotion expression and regulation), which may in turn modify susceptibility and resilience to psychological distress. Thus, differences in stress-elicited neural reactivity may represent an important neurobiological mechanism underlying discrimination-related mental health disparities.