New research suggests an explanation for the relationship difficulties experienced by people with borderline personality disorder.

Investigators from the University of Georgia used functional magnetic resonance imaging (fMRI) to discover that those with borderline personality disorder (BPD) have lowered brain activity in regions important for empathy. BPD is a mental illness marked by unstable moods.

“Our results showed that people with BPD traits had reduced activity in brain regions that support empathy,” said the study’s lead author Dr. Brian Haas, an assistant professor in the Franklin College of Arts and Sciences psychology department.

“This reduced activation may suggest that people with more BPD traits have a more difficult time understanding and/or predicting how others feel, at least compared to individuals with fewer BPD traits.”

The findings appear in the journal Personality Disorders: Theory, Research, and Treatment.

For the study, Haas recruited over 80 participants and asked them to take a questionnaire, called the Five Factor Borderline Inventory, to determine the degree to which they had various traits associated with borderline personality disorder.

The researchers then used imaging to measure brain activity in each of the participants. During the fMRI, participants were asked to do an empathetic processing task, which tapped into their ability to think about the emotional states of other people, while the fMRI measured their simultaneous brain activity.

In the empathetic processing task, participants would match the emotion of faces to a situation’s context. As a control, Haas and study co-author Dr. Joshua Miller also included shapes, like squares and circles, that participants would have to match from emotion of the faces to the situation.

“We found that for those with more BPD traits, these empathetic processes aren’t as easily activated,” said Miller, a psychology professor and director of the Clinical Training Program.

Haas chose to look at those who scored high on the Five Factor Borderline Inventory, instead of simply working with those previously diagnosed with the disorder. By using the inventory, Haas was able to obtain a more comprehensive understanding of the relationship between empathic processing, BPD traits, and high levels of neuroticism and openness, as well as lower levels of agreeableness and conscientiousness.

“Oftentimes, borderline personality disorder is considered a binary phenomenon. Either you have it or you don’t,” said Haas, who runs the Gene-Brain-Social Behavioral Lab.

“But for our study, we conceptualized and measured it in a more continuous way such that individuals can vary along a continuum of no traits to very many BPD traits.”

Haas found a link between those with high borderline personality traits and a decreased use of neural activity in two parts of the brain: the temporoparietal junction and the superior temporal sulcus, two brain regions implicated to be critically important during empathic processing.

The research provides new insight into individuals susceptible to experiencing the disorder and how they process emotions.

“Borderline personality disorder is considered one of the most severe and troubling personality disorders,” Miller said. “BPD can make it difficult to have successful friendships and romantic relationships. These findings could help explain why that is.”

In the future, Haas would like to study BPD traits in a more naturalistic setting.

“In this study, we looked at participants who had a relatively high amount of BPD traits. I think it’d be great to study this situation in a real life scenario, such as having people with BPD traits read the emotional states of their partners,” he said.

Source: University of Georgia Abstract of the brain photo by shutterstock.