Research on borderline personality disorder suggests frontal brain activity drives increased amygdala activity

Problems with the regulation of emotion in borderline personality may be caused by frontal brain activity, according to a study published this June in Brain Imaging and Behavior. The research suggests that borderline personality disorder involves a feedforward system in which input from frontal brain regions – conscious thoughts and cognitions – are driving excessive amygdala activation.

Borderline personality disorder is a serious condition affecting the way a person regulates emotion, which primarily involves increased sensitivity to negative information. Consequently, individuals with borderline personality disorder engage in a number of dangerous behaviors such as self-injury and suicide attempts, and also have problems in a number of areas, including with themselves, relationships, work and leisure.

Research on the brain has highlighted significant differences in the functioning of brain between the limbic system and frontal regions in patients with borderline personality disorder. More specifically, in the area of the brain which is important for processing emotion – the amygdala – research has shown that there is greater activation when viewing negative information, when angry, and when recalling unresolved life events.

Research also indicates that there are differences in activation between conscious and unconscious processing, which provides insight into the mechanisms through which individuals with borderline personality disorder process information.

For the study, led by Kathryn Cullen of the University of Minnesota Medical School, 12 women with borderline personality disorder and 12 control women participants underwent an fMRI (Functional magnetic resonance imaging) scanning session in which participants passively viewed emotional faces (fear, happy and neutral expressions). Emotional faces were presented in two conditions; either overtly to measure the conscious processing of emotion or covertly to measure the automatic, unconscious processing of emotions (faces were very quickly presented for 26ms before being switched to neutral faces).

The results revealed that in response to overt fear, borderline personality disorder patients showed greater activation both in left amygdala and in several frontal cortical regions. In response to covert fear and covert happy stimuli, the borderline personality disorder group also showed greater activation than controls in several regions including frontal and temporal cortical regions.

The researchers concluded that, “greater amygdala and cortical activation than controls during overt but not during covert fear are supportive of the hypothesis that emotion dysregulation in this group is primarily due to dysfunction in cortical regulation of emotion, and suggestive of the possibility that BPD involves a feedforward system in which frontal input may, in part, drive excessive amygdala activation.” In other words, conscious thoughts and cognitions related to frontal brain regions may lead to increased amygdala activity and emotional sensitivity.