Brain regions that process anger and sadness are overactive in people with borderline personality disorder, a new University of Toronto study reveals. Additionally, the research finds that the areas of the brain that would normally help dampen negative emotion are underactive.
The work offers the best description yet of the neural circuits that underlie the severe mental illness and could lead to better treatments and diagnosis.
Although a number of brain imaging studies have found differences in the function of brains of people with borderline personality disorder (BPD), some of the studies have been contradictory.
For the study, a team led by Anthony C. Ruocco, assistant professor in the department of psychology and program in neuroscience at the University of Toronto, analyzed data from 11 previously published studies and confirmed a number of important differences between people with BPD and those without.
Hyperactive and Underactive Brain Regions
On the one hand, a brain area called the insula, which helps determine how intensely we experience negative emotions, is hyperactive in people with BPD. On the other hand, regions in the frontal part of the brain, which are thought to help us control our emotional reactions, are underactive.
“It’s not just that they have too much drive from their emotions,” Ruocco says. “They seem to have less of the ‘brakes’ to try to curb those emotions and to help regulate their intensity.”
The findings fit well with symptoms seen in people with BPD, Ruocco says:
“The hallmark symptom that people describe is emotion dysregulation—you’re happy one moment, and the next moment you’re feeling angry or sad or depressed. People with BPD can cycle through emotions, usually negative ones, quite rapidly.”
More important is how the findings might be useful in diagnosis and treatment. One challenge is that BPD often occurs with other disorders, such as major depression, which can make it harder to identify and treat.
The new results raise the possibility that brain imaging could be used to make a more definitive diagnosis of BPD, Ruocco says.
In the future it might also help determine what treatments are most likely to be effective for an individual patient, based on what the imaging studies show about their brain function before they even begin treatment.