Neuroeconomic adaptation to norm shifts is preserved in borderline personality disorder.

objectiveBorderline personality disorder (BPD) is characterised by instability in interpersonal relationships, self-image, and affect. Dysregulated negative emotional processing involving prefrontal and limbic circuits is considered a neural basis of BPD. However, it remains unclear how prefrontal modulation of social decision-making in BPD differs from non-psychiatric controls.

methodsTo investigate social decision-making in response to unfairness, we conducted an functional magnetic resonance imaging study involving adults with a diagnosis of BPD (

resultsCumulative rejection rates indicated that individuals diagnosed with BPD exhibited consistent differences in overall offer rejection rates but similar adaptation to HC when responding to norm shifts. Preservation of normative social decision-making in BPD (no significant difference vs. HC) was evident in regression analyses of rejection rates and in reinforcement learning models, with no group differences observed in Rescorla-Wagner parameters. Furthermore, we detected no significant neural activation differences between groups, although ventral regions of the medial prefrontal cortex were preferentially involved in valence-related rather than salience-related polynomial modulation.

conclusionContrary to our hypotheses, neither behavioural nor neural responses to economic norm violations differed significantly between BPD and HC groups across one-shot games involving unknown partners. Future research could explore whether more personally relevant or higher-stress social contexts elicit differences not observed here.