It has become clear that racism and other forms of social discrimination have a negative impact on health outcomes. Only recently, though, have scientists begun to see how this plays out within the neural structures of the brain.

“It’s important to recognize that these everyday forms of discrimination — things we sometimes hardly take note of from a societal perspective — may be influencing how our patients cope with their illnesses,” says Dr. Uraina Clark, a brain researcher at the Icahn School of Medicine at Mount Sinai in New York City. “So, it’s even more important that we ensure that all of our patients have access to effective systems of care that are able to help them maintain their resilience and well-being.”

Clark spoke at the recent meeting of the American Academy of Neurology (AAN) about her research in this area. A study she published in 2018 was one of the first to link the functional activity within the amygdala to the stress of social discrimination in marginalized groups.

The amygdala — an area of the brain that plays an important role in complex psychosocial behavior — shows heightened activity in individuals under stress. This includes the fight-or-flight response, processing of ambiguity, and matching environmental cues with emotion and relevance.

Clark said her study shows there is evidence that an increase in activity in the amygdala caused by social discrimination affects regions of the brain that control how individuals act and feel.

Seventy-four adults from known marginalized groups based on gender, race, and sexuality were included in the study. The majority of the participants (72 percent) identified as African-American, while others identified as female, Hispanic, and homosexual/bisexual.

Clark and her team used resting-state functional magnetic resonance imaging (fMRI) to analyze brain activity. They compared this to subjects’ self-reported experiences of social discrimination using the Everyday Discrimination Scale (EDS).

The EDS is a nine-item survey that rates the frequency of everyday discriminatory experiences. Examples include “You are treated with less courtesy than other people” and “People act as if they think you are not smart.”

The researchers found that as self-reported scores of social discrimination increased, so too did spontaneous activity within the amygdala. The study also showed that more frequent connectivity between the amygdala and other areas of the brain mirrored the rise in perceived discrimination by the individual.

Researchers controlled for levels of current stress, depression, anxiety, and PTSD-related symptoms. They also factored in age, sex, race, ethnicity, and sexual orientation.

Clark and her colleagues have continued to look at the effect of social discrimination on the brain. She said she has also found a correlation between greater frontal lobe thickness and certain coping strategies used in response to social discrimination.