The Rewarding Nature of Anger Rumination in Borderline Personality Disorder: An fMRI Investigation

OF DISSERTATION THE REWARDING NATURE OF ANGER RUMINATION IN BORDERLINE PERSONALITY DISORDER: AN FMRI INVESTIGATION Anger rumination, or persistently dwelling on feelings of anger, is associated with borderline personality disorder (BPD) and related features, such as aggressive behavior and cognitive distortions. To develop more effective treatments, it is crucial to understand why individuals with BPD engage in anger rumination despite its negative outcomes. The activation of energy associated with anger, as well as feelings of justification and validation, may be experienced in the short-term as rewarding. This may prevent individuals with BPD from attempting to reduce their rumination. Functional magnetic resonance imaging (fMRI) and behavioral methods were utilized to examine this theory in a sample of women diagnosed with BPD (n=13) and healthy controls (n=15). In an initial session, all participants were an administered a diagnostic interview for BPD, as well a series of self-report measures. In a second session, all participants completed an essay-writing task prior to the fMRI scan. All participants were provided with identical, highly critical feedback about their essays from a supposed essay evaluator. In response to this interpersonal provocation, participants with BPD demonstrated higher activation in brain regions associated with self-conscious reactivity to errors (insula, ventrolateral prefrontal cortex). Subsequent directed provocationfocused thought, compared to neutral-focused thought, produced greater activation in regions previously associated with anger rumination (dorsomedial prefrontal cortex, lateral orbitofrontal cortex) across groups. As hypothesized, anger rumination, relative to neutral-focused thought, produced greater activation in brain regions associated with reward and pleasure (nucleus accumbens) for the BPD group only. No significant differences were observed for self-focused thought. Following the directed rumination task, participants completed a competitive reaction time task that provides an opportunity for participants to act aggressively, supposedly against their essay evaluator. The BPD group demonstrated significantly higher levels of aggressive behavior; however, no significant group differences emerged in neural functioning during the task. These findings suggest that anger rumination may be positively reinforcing for individuals with BPD, which has implications for treatment approaches.