The nature of borderline personality disorder: multiple dimensions, multiple symptoms, but one category.

Borderline personality disorder (BPD) is a multidimensional syndrome that is not rooted in a single diathesis. Each of its features (affective instability, impulsivity, unstable relationships, and cognitive defects) reflects different diatheses. BPD differs from other Axis II disorders in its high level of symptoms, but is not a variant of an Axis I disorder and is difficult to describe through dimensional traits. This review suggests that BPD needs to be diagnosed with a narrower set of criteria that cover all of its domains. In the long run, the disorder will need to be redefined on the basis of its etiology and pathogenesis.