Self and identity in borderline personality disorder: Agency and mental time travel.

We consider how conceptions of the self and identity from the philosophical literature can help us to understand identity disturbance in borderline personality disorder (BPD). We present 3 philosophical approaches: connectedness, narrative, and agency. We show how these map on to 3 different ways in which the self can be temporally extended. The connectedness approach is dominant in philosophy, and the narrative approach has been used by psychiatry, but we argue that the lesser-known agency approach provides a promising way to theorize some aspects of identity disturbance in BPD. It relates the 2 diagnostic criteria of identity disturbance and disinhibition and is consistent with evidence of memory deficits and altered self-processing in BPD patients.