Over the past fifteenyears, access to evidence-based psychological interventions (EBPIs) for borderline personality disorder has dramatically increasedin the United Kingdom. However, some patients continue to fall through the gaps. This paper presents a novel analysis of evidence on patients who are currently unable to benefit from EBPIs and explores possible solutions, with particular reference to dialectical behaviour therapy and mentalization based therapy.At one end of the spectrum, patients with less severe difficulties often do not meet the threshold for receiving EBPIs in dedicated personality disorder services. The nascent evidence base for a possible solution —implementation of streamlined versions of EBPIs in generic mental health or even primary care services —is reviewed. At the other end, asizeable minority of patients receiving long-term EBPIs discontinue treatment prematurely and/or experience poor outcomes. This is a highly distressing experience with potential for iatrogenesis—yet the evidence base for what to do next is non-existent and follow-on treatment pathways in services are unclear. Difficulties in the therapeutic alliance, a failure to overcome epistemic hypervigilance, and therapist non-adherence to the model are reviewed as possible contributing factors. The importance of understanding the patient perspective on what happened, considering the role of both patient and therapist in contributing to difficulties, and offering patients a choice in specifying their onward treatment, is discussed. Finally, increasing access to trauma-focussed EBPIs for post-traumatic stress disorderis recommended as an avenue for the future
