Racism has negatively impacted generations of people, leading to discrimination, lost economic opportunities, racist policing and incarceration, and in many cases, death.
The data are already concerning.
Experiences of racial discrimination are consistently linked with mental health issues such as depression, anxiety, substance use and PTSD, as well as physical ailments such as diabetes, hypertension and obesity. Black Americans, for instance, are about twice as likely as White Americans to develop dementia.
Racism is its own stressor and one that cannot be easily avoided.
“Even as a kid, you’re experiencing discrimination related to your skin color, you can’t really change that,” said Arpana Gupta, associate professor at the University of California at Los Angeles.
Black people and other racial minorities — and their brains — can learn to adapt, but it comes at a cost, researchers said.
“It’s kind of like working twice as hard to get just as far,” said Negar Fani, associate professor of psychiatry and behavioral sciences at Emory University School of Medicine.
Over the long term, racism accelerates aging and degrades key brain circuits involved in regulating emotion and cognition.
“This is not an effect of race,” said Nathaniel Harnett, neuroscientist at McLean Hospital and an assistant professor of psychiatry at Harvard Medical School. “It is an effect of the burdens we place on racial groups.”
Constant vigilance and racial stress wear down the brain
Recent neuroimaging research shows that encounters with racial discrimination on the individual level and structural racism at the societal level change how the brain responds to potential threats.
Racial discrimination is a type of trauma that is often invalidated or questioned by society, Fani said.
“The idea that someone has been discriminated against is often questioned,” she said. “And that has led to a lot of individual invalidation. So people self-invalidate when things happen to them.” This in turn can lead to rumination over their experiences and increased vigilance for future racist threats, she added.
In a 2021 study published in JAMA Psychiatry, Fani, Harnett and their colleagues found that among 55 Black women who had experienced some form of childhood or adult trauma, those who reported experiencing more racial discrimination had proportionately higher neural responses in brain regions related to threat vigilance and emotional regulation. At the same time, there was also increased activation in visual brain areas involved with visual attention, suggesting that they may be more attentive to their environments.
Vigilance has a function in the presence of a threat, racial or otherwise, by helping us detect and get away from it. And in the short term, increased vigilance can be adaptive. In the study, the Black women who reported experiencing more racial discrimination performed better on an attention task.
But with long-term stress come long-term changes to the brain. “The issue with aspects of racism, like racial discrimination and structural racism, is that these things are ever-present,” Harnett said.
In a 2019 study, Harnett and his colleagues examined the differences between 198 Black and White young adults who responded to a threatening loud sound.
The researchers found that White individuals had much larger reactivity to the stressor than Black individuals. White participants had increased skin conductance and activation of neural circuits involved with threat-related emotional processing, including the prefrontal cortex, hippocampus and amygdala.
But when the researchers took into account negative life experiences — indexes of structural racism such as violence exposure and neighborhood disadvantage — these differences between White and Black subjects went away.
This suggests that real-life adversity for many of the Black subjects was contributing to an “almost blunting of emotion to laboratory stress,” Harnett said.
“A little bit of stress is probably good for you,” he said. “It’s probably good to have a little bit of adversity because you learn to regulate, you learn to overcome it.”
Problems arise when the stress is persistent, as the direct and indirect effects of racism often are. “At a certain point, you reach the end of the resources that you have to actually continue regulating,” Harnett said.
Racial stress is linked to more medical issues
Chronic and constant racial stress contributes to allostatic load, the cumulative burden on and “wear-and-tear” of the body and overall health. Neuroimaging data shows that racial discrimination is associated with degradation in the brain’s gray and white matter in cognitive and emotional regulation areas.
“Our brains aren't really designed to constantly be engaging in effortful attention regulation or emotion regulation,” Fani said.
In one 2022 study, Fani, Harnett and their colleagues reported that among 81 Black women who had experienced trauma, those who reported experiencing more racial discrimination showed proportionally thinner gray matter in the cingulate cortices.
In another study from the same year, Fani and colleagues found that racial discrimination also compromises the integrity of white matter — the neural connections — of the prefrontal cortex, a key brain area for behavioral self-regulation. Loss of these connections, in turn, was associated with more overall medical issues.
This could make sense if the loss of white matter impacted the capacity to self-regulate, Fani said. If they are emotionally eating, turning to drugs or not exercising as a result, the Black female study subjects “may have a greater vulnerability to health problems that are related to these behaviors like diabetes, metabolic problems, cardiovascular disease.”
In this way, the harm from racism is a whole-body problem that interacts and feeds on itself.
“We’re not linear,” Gupta said. “As humans, our biology is impacting our behavior, and it’s impacting our environment, but then our environment is also impacting our biology.”
In a 2022 study of 154 participants who were White, Black, Hispanic and Asian, Gupta and her colleagues reported that discrimination, in general, was correlated with anxiety and depression.
For Black and Hispanic individuals, discrimination was also associated with altered brain connectivity associated with psychological coping as well as more systemic inflammation of the gut and microbiome, which can also have an adverse effect on mental health.
“How we treat people and how we're treated really has a huge impact on our biology,” Gupta said.
Coping with racial discrimination and having hope
Knowing that racial discrimination impacts our biology and brain raises “a really empowering question,” Gupta said. “Is there some way that we can change the biology to deal with this negative racism or this discrimination?”
Brain-directed treatments such as cognitive behavioral therapy and mindfulness sessions with therapists and counselors trained in racial stress may help, Gupta said. Medications for reducing stress and addressing mental health may also help. And seeking or building support networks with peers to commiserate and share experiences can be essential, as racial trauma is often not publicly acknowledged.
When Fani speaks with communities about her research, she said many people express appreciation for their experiences being validated and gratitude for some public scientific recognition of their experiences.
“For them, well, this is not rocket science. Of course, this is true,” Fani said. “But I think there’s some relief that there’s some public acknowledgment that this is racism that’s causing these effects and not just being Black.”
Before George Floyd was murdered by a Minneapolis police officer and the racial reckoning of his death, research around race and racial discrimination was not popular, and there was even resistance from the scientific community over acknowledging racism as its own type of trauma and stress, Fani said. Now, there is more interest, funding and research, which are already leading to better understanding.
“I’m hoping that in making this invisible stuff visible, it helps people feel a greater sense of self-validation, like that their responses to the trauma are valid and normal,” she said. “And not pathologizing those responses.”
“Things change slowly. It’s an uphill battle, but they do change,” Harnett said. “And I do think that more people care about this now in a way that is tangible, and feels like things are moving forward than they might have several years ago.”
Do you have a question about human behavior or neuroscience? Email BrainMatters@washpost.com and we may answer it in a future column.