Purpose This study aims to explore the lived experience of loneliness among a group of people diagnosed with the contested diagnosis of borderline personality disorder (BPD). In so doing, it contributes to works offering dimensional conceptualisations of personality disorders and contributes to loneliness study more broadly which has seen a rise in interest since the Covid-19 epidemic and the subsequent enforced isolation and the resultant new phenomenon of sudden loneliness. Design/methodology/approach Participants with diagnoses of BPD were recruited through a combination of calls through online fora and announcements at self-help groups. A total of 25 people made contact, with interviews eventually being carried out with 14 of these. They were invited to take part in unstructured, recorded one-to-one interviews. Thematic analysis was used in this study, which used a narrative phenomenological approach using an Arendtian lens. Findings Through attending to the interwoven themes in the narratives of trauma, loss and loneliness, it emerged that the enduring loneliness experienced was compounded by repeated instances of testimonial injustice. Research limitations/implications This study supports the need for a further deepening of our understanding of the complexity of experience at the interface of loneliness and mental ill health. Practical implications This study critiques the reductive assumptions behind websites, simplistic tool kits and training within the mental health arena dictating “what works” for loneliness. The paper argues for health professionals to develop a more nuanced listening to reported loneliness and that part of what may compound this complex experience among people diagnosed with personality disorder is epistemic injustice, rife within a climate of neoliberalism. Social implications Neoliberalism has been identified as a key driver of distinct shifts in mental health policy and the commodification of mental health. Its fixation with medicalisation and its drive to treat “mental illness” as a problem within the individual positions people as self-contained agents and downplays, or worse, ignores the social, cultural and economic dimensions that contribute to the person’s distress. Neoliberalism’s discourse of “responsibilization” for example, urges individuals that families, communities and workplaces rather than publicly funded services become the main resources to respond to in times of mental distress. This, however, assumes a concreteness to these institutions which may be illusory and leaves those in difficulty dependent on presumed immediate social circles. These circles, however, if they exist, may contain the very people who have failed individuals or subjected them to the testimonial injustices so often cited in the narratives of this research. Originality/value The Arendtian account of loneliness rests on the premise that the human being of contemporary society is afflicted with a sense of isolation and homelessness, further exacerbated in today’s neoliberal context. By drawing on this account, the enmeshed and complex nature of mental illness, loneliness and dislocation from society and the ways in which continued epistemic injustice negatively impact on mental well-being are laid bare. Phenomenology of loneliness goes some way to helping people without the devastating life experiences common to those diagnosed, rightly or not, with a personality disorder gain a sense of the experience, and this research argues for psychological practice to be more mindful of this literature and the value of closely heard first-person narratives.