Attachment orientations and borderline personality features: the mediating role of difficulties in interpersonal emotion regulation

Background: Insecure attachment predicts borderline personality (BP), with emotion regulation widely recognized as a key mediator of this association. While interpersonal difficulties are central to BP, most studies have focused on intrapersonal emotion regulation, overlooking its interpersonal forms. Given the importance of understanding emotional and relational dysfunctions in BP, this study examined difficulties in Interpersonal Emotion Regulation (IER), investigating the role of maladaptive strategies—venting and excessive reassurance-seeking—as mediators in the relationship between attachment insecurity and BP. Methods: A total of 420 adults completed self-report measures assessing BP features (PAI-BOR: affective instability, identity disturbances, negative relationships, and self-harm), attachment orientations (ECR-12: attachment anxiety and attachment avoidance), and IER difficulties (DIRE: venting and reassurance-seeking). Pearson’s correlations tested associations among variables, and a path analysis was conducted, using attachment anxiety and avoidance as exogenous variables, IER difficulties as mediators, and BP features as outcome variables. Results: Attachment anxiety was positively associated with all BP features and greater difficulties in IER (venting and reassurance-seeking). IER mediated the relationship between attachment anxiety and BP features, with venting significantly mediating all BP dimensions. Conclusions: Findings highlight a self-perpetuating cycle of relational difficulties and emotional dysregulation in BP, with IER playing a crucial role. Excessive reliance on others for emotional regulation, likely stemming from mentalization impairments, may lead individuals with BP and anxious attachment to externalize distress, reinforcing negative moods and straining relationships. Psychological interventions should focus on breaking this cycle by enhancing emotion regulation abilities, fostering autonomy, and reducing maladaptive dependence on others for emotional relief.