Re-evaluating the distinction between Axis I and Axis II disorders: the case of borderline personality disorder.

The division between Axis I clinical syndromes and Axis II personality disorders is a long-standing distinction based primarily on three guiding principles: phenomenology, cause, and course. Clinical syndromes were generally thought to be characterized by transient symptoms with biological causes and an unstable course; personality disorders were supposed by many to be characterized by long-standing personality traits, whose roots were primarily psychological, and a stable and unremitting course. Borderline personality disorder (BPD), however, is a condition characterized by distinct clinical symptoms, varied causes, and a relatively unstable course. Past theorizing about the distinction between Axis I and Axis II disorders is presented in light of recent empirical evidence refuting the rationalization for the separation of personality disorders and clinical syndromes using BPD as a means for comparison. (c) 2005 Wiley Periodicals, Inc. J Clin Psychol 61: 1509-1523, 2005.