Integrating autonomic and affective pathways in borderline personality disorder: the triangle therapy hypothesis

Introduction Borderline personality disorder is marked by emotional lability, unstable identity, and hypersensitivity to abandonment. Although mainstream treatments, such as dialectical behavior therapy, schema therapy, and mentalization-based therapy, reduce symptoms, they often bypass the subcortical affective systems shaped by early attachment trauma. This conceptual paper presents triangle therapy for borderline personality disorder, a neuroaffective intervention based on the premise that three ancestral affective conditions—silence, sound, and isolation—are hypothesized to shape autonomic dysregulation in borderline personality disorder. Method Triangle therapy for borderline personality disorder proposes a 30-session protocol involving progressive exposure to each condition over ten sessions. Stimulus duration would increase from 5 to 50 min under continuous therapist attunement without verbal interpretation. The model emphasizes embodied co-regulation to support potential autonomic integration of historically overwhelming affective states. Hypothetical results Potential outcomes may include recalibration of vagal and sympathetic tone, extinction of catastrophic prediction errors, and emergence of symbolic-affective processing. The model integrates polyvagal theory, affective neuroscience, and psychodynamic frameworks on early neglect. Safety protocols and inclusion criteria are specified to support empirical evaluation. Discussion Triangle therapy for borderline personality disorder is a theoretical model proposed to inform future research and clinical development. It is not a replacement for existing evidence-based treatments but is framed as a somatic pre-phase that may improve affective tolerance and therapy engagement. Empirical testing through pilot studies and multimodal physiological assessment is essential before clinical implementation. The protocol aims to provide new opportunities for treating severe affective instability in outpatient and inpatient settings.