Mark L. Ruffalo
Debate about borderline personality disorder (BPD) has intensified, with some proposing its absorption into complex post-traumatic stress disorder and others questioning whether the diagnosis is harmful. These debates often obscure the central issue of construct validity. This paper evaluates whether BPD constitutes a coherent clinical entity. Drawing on Robins and Guze's classic diagnostic validators - symptom specificity, heritability, course of illness, biological markers and treatment response - the evidence demonstrates that BPD is a robustly validated psychiatric disorder that should be retained in future classification systems. Concerns about stigma and dimensional models are considered but do not undermine its empirical grounding.