What Happens in a Borderline Man's Brain When He Gets Mad?
New research explores the neuroscience behind the borderline man’s rage.
Posted Dec 29, 2018
An inability to control intense rage is one of the hallmark qualities of borderline personality disorder (BPD). When their rage explodes into violent actions, people with this disorder can suffer a number of negative life consequences, from losing their close relationships to jeopardizing other people’s physical well-being and possessions. If you’ve ever been in an argument with an individual who has this disorder, you know how quickly the disagreement can devolve into violence. As much as you may care for this other person, you know that to protect your safety, you’ve got to get out of there — and fast.
Men with borderline personality disorder who are prone to becoming furious at small provocations can be particularly dangerous, both to themselves and those around them, due to having greater physical strength than that typically possessed by women. The enraged borderline man may throw and break whatever objects he can get his hands on and threaten to hurt, or actually hurt, the people around him whom he perceives as thwarting his needs. According to University of Heidelberg’s Katja Bertsch and colleagues (2019), men with borderline personality disorder who act angrily and aggressively toward others can end up in jail due to their impulsive and uncontrolled behavior. The consequences, then, can be severe and life-changing.
The German researchers believe that there may be neural mechanisms which underlie the tendency for men with BPD to show such extreme, anger-related aggression. The so-called “fast emotional biases” that lead them to overreact may, Bertsch et al. believe, reflect deficiencies in the area of the brain known as the lateral prefrontal cortex. This is the part of the brain that evolves later in development and is designed to send signals to the more primitive areas of the brain that respond quickly to potentially threatening stimuli. These subcortical, lower-order areas of the brain do a good job protecting you from actual threats to your safety, such as getting you to run out of the way of an oncoming car. However, they will also fire up when triggered by the perception of an emotionally threatening situation. It’s up to the higher regions of the cortex to keep your behavior in check when there is no actual threat. The instinctual prompt to run or hit back occurs first (hence the idea that it’s “fast”) and only secondarily gets turned off when the more advanced cognitive processes in the cortex show that the threat is not real.
If the lateral prefrontal cortex is in fact deficient in men with BPD, this would explain why they act on their initial instincts in a potentially threatening situation, rather than taking a more measured approach in which they determine whether such action is indeed necessary. Previous research by the Heidelberg neuroscientists identified deficiencies in the lateral prefrontal cortex in emotional processing by women with BPD and by psychopathic male criminal offenders. The purpose of their study on male BPD patients was to determine whether a similar lack of inhibition by the higher brain regions occurs in these individuals as well.
To determine whether the brains of men with BPD would react differently to threatening stimuli than the brains of non-clinical men, Bertsch et al. devised an experimental manipulation to test their reactions while viewing either happy or angry faces on a screen while their brains were scanned in an MRI machine. At the same time, they held a joystick that recorded their reaction times to the experimental instructions. These instructions took two forms, yielding "incongruent" and "congruent" conditions. In the incongruent condition, the men were told to push the joystick toward the screen when an angry face appeared and to pull it away from the screen when the face on the screen was happy. In the congruent condition, they pushed toward the happy face and pulled away from the angry face on the screen. Because people tend to approach happy faces and avoid angry ones, it should take more cortical control to resist the impulse to push toward the happy face and instead pull away from it. The difference between the affect incongruent and affect congruent conditions therefore became the measure of the individual's ability to suppress those "fast" emotional biases (i.e., to be drawn to a happy face).
Having established diagnoses of the participants from standard measures, as well as controlling for depression, attention-deficit hyperactivity disorder, anxiety, impulsiveness, and anger, the authors were then able to compare the activation of the key parts of the brains between men with and without BPD in this experimental manipulation. The sample consisted of 15 men who met the diagnostic category for BPD and 25 age- and intelligence-matched controls.
Consistent with studies involving female BPD patients and criminal men with high psychopathy scores, the men with BPD did not engage part of their lateral prefrontal cortex in response to incongruent trials to the same extent as the controls. Furthermore, on the self-report scales of anger control, BPD men with lower cortical activation reported higher levels of angry acting-out. Another piece of the puzzle was a subcortical area of the brain involved in anger, the amygdala, which exhibited more activation in BPD men who reported a strong tendency to act out when angry.
For men with BPD provoked by emotional situations and stimuli, the German findings suggest that their tendency to act out may reflect a diminished control by the parts of the brain that function to reduce such aggressive reactions. Whether such deficits are programmed into the brains of these individuals or become manifest over time is not clear from the present correlational study. Furthermore, the experimental manipulation involved comparing congruent and incongruent responses to happy or angry faces without determining the actual moods of the participants in the study at the time. If a man was feeling angry, pushing the joystick toward the angry face could have been a mood-congruent action.
To sum up, and with these caveats in mind, the German study suggests a potential approach to understanding the rage that can overwhelm the man with BPD. Whether these deficits are the cause or the effect of a lifetime of defective anger control, it appears that there may be something biological involved in his lack of inhibition when he becomes provoked. Information such as that put forward by this study could provide a novel approach to intervention, perhaps allowing men with this very difficult disorder to identify their potentially damaging fast emotional biases and, over time, gain control over them.
Bertsch, K., Krauch, M., Roelofs, K., Cackowski, S., Herpertz, S. C., & Volman, I. (2018). Out of control? Acting out anger is associated with deficient prefrontal emotional action control in male patients with borderline personality disorder. Neuropharmacology. doi 10.1016/j.neuropharm.2018.12.010