ABSTRACT
Borderline personality disorder (BPD) is widely presented as an objective psychiatric diagnosis describing emotional and relational distress. However, feminist, decolonial, neurodiversity and lived experience-led scholarship demonstrates that BPD emerged within colonial, cisheteronormative, misogynist and neuronormative epistemologies that moralise distress and regulate identity, self-expression and access to care. This paper critically examines BPD as a diagnostic construct and governance technology that produces iatrogenic harm through epistemic injustice, structural exclusion and moralised interpretations of need. It explores how the diagnosis discredits lived experience knowledge, justifies care withdrawal and obscures sensory, cultural and structural determinants of distress and considers the implications for mental health nursing practice. A critical discourse analysis was conducted across psychiatric literature, policy documents, historical diagnostic texts and lived experience scholarship, treating psychiatric language and categorisation as technologies of power shaping credibility and clinical response. The analysis shows that BPD operates less as a clinical description than as a regulatory framework maintained through gendered, colonial and cisheteronormative norms. Dominant narratives of dependence, attachment theory and emotional expression obscure trauma, sensory differences and structural violence, while legitimising coercive and exclusionary practices. Mental health nurses are positioned at the frontline of enacting these logics, often experiencing moral distress. The BPD diagnosis lacks epistemic, cultural and ethical legitimacy. Its continued use undermines therapeutic safety and trust. A harm reduction transition away from the BPD construct is required, prioritising relational safety, sensory-informed and culturally responsive care, epistemic humility and lived experience leadership.