Who am I? A Phenomenology of Identity Disturbance in Borderline Personality Disorder

This thesis provides a novel phenomenological account of identity disturbance in borderline personality disorder (BPD). BPD is a psychiatric illness characterised by instability in one’s identity, interpersonal conflict, difficulties in emotion regulation, and suicidality (American Psychiatric Association, 2022b). Currently, BPD research focuses primarily on the diagnostic criterion of emotion dysregulation, interpreting this as the main component of the disorder. However, by doing so it fails to fully acknowledge the effects an unstable sense of self, also known as identity disturbance, has on the patient’s thoughts, behaviours, and actions. Moreover, those that have attempted to emphasise identity disturbance fall short in their methods. They argue either that (1) identity disturbance is a result of the patient’s inability to form a coherent narrative about their life, or (2) identity disturbance is the term given to a collection of common experiences of self-inconsistency. In doing so, two problems arise: (1) they assume that a person’s ability to narrate their life determines their sense of self and (2) that experiences such as “patient sometimes feels unreal” have clear and determined meanings. These problems lead to a misunderstanding of BPD, ultimately impacting on how effective current treatments are. With the combined use of phenomenological psychopathology and empirical studies, I offer a reconceptualisation of identity disturbance as a multifaceted construct which consists of alterations to one’s self-other-world relation. I argue that the phenomenological core of identity disturbance should be understood as disturbed self-experience which details an alienation and subsequent breakdown in communication between one’s pre- reflective and reflective self-awareness. I then apply this new understanding to the behavioural manifestations within the disorder, progressing our knowledge of how experiences of dissociation and chronic feelings of shame occur. By highlighting the role of disturbed self-experience in identity disturbance, my research will advance our current perception of BPD, bridging the gap between philosophy, psychiatry, and psychology. Thus in highlighting the importance of identity disturbance in BPD, primary treatments like dialectical behavioural therapy (DBT) can benefit from this newfound research.