[The borderline syndrome: conceptual problem, theoretical models, nosographic location]

The historical vicissitudes of the term "borderline" in psychiatric literature as well as its actual conceptual dimension are reviewed. The latter is exposed organized in categories or theoretical models as follows: as a peculiar or attenuate presentation of a psychosis, a grave form of a neurosis, a passage syndrome between a neurosis and a psychosis, or an independent nosographic picture. In mentioning pathochronic and generic aspects, an intent of unitary conceptualization is outlined which comprises: I) the clinical picture which translates ego pathology into behavioral terms with a "longitudinal" symptomatological hierarchization of functional levels which interact simultaneously sometimes (dynamic psychopathological space-time) and pointing out its dependence on the environment; II) the structural analysis or the dynamic formulation. The actual nosographic position of the borderline syndrome as well as the one established in the proposed Third Review of the American Psychiatric Classification and its heuristic value are examined. Finally, the presence of this syndrome in relation to modern time society characteristics is commented.