Background: Health practitioners have long recognised that a proportion of patients with Borderline Personality Disorder (BPD) struggle to improve even after being provided with evidence-based treatments. Despite this, there are few studies and little known about the size and factors behind non-response. This thesis by compilation presents three studies exploring non-response to psychotherapy for BPD. Method: First, a systematic review was conducted to obtain an informed estimate from the literature on the proportion of people who are not responding to psychotherapy for BPD (Chapter Two). Seco...