Borderline personality disorder, complex trauma, and problems with self and identity: A social‐communicative approach

Borderline personality disorder (BPD) is a relatively highly prevalent psychiatric disorder that is associated with very high personal and socioeconomic costs. This paper provides a state-of-the-art review of the relationship between complex trauma and key features of BPD, with a focus on problems with self-coherence and self-continuity. We first review evidence for the high prevalence of complex trauma in BPD patients. This is followed by a discussion of emerging knowledge concerning the biobehavioral mechanisms involved in problems related to self and identity in BPD. We emphasize three biobehavioral systems that are affected by complex trauma and are centrally implicated in identify diffusion in BPD: the attachment system, mentalizing or social cognition, and the capacity for epistemic trust-that is, an openness to the reception of social communication that is personally relevant and of generalizable significance. We formulate a new approach to personality and severe personality disorders, and to problems with self and identity in these disorders, rooted in a social-communicative understanding of the foundations of selfhood. We also discuss how extant evidence-based treatments address the above-mentioned biobehavioral systems involved in identity diffusion in BPD and related disorders, and the supporting evidence. We close the paper with recommendations for future research.