[The borderline patient. Diagnosis, psychodynamics and physician-patient relation].

'Borderline' is a popular psychiatric diagnosis. The uses of the term are variable and often unclear. It is the goal of this presentation to elaborate a borderline concept for use in daily clinical practise. First, development of the term over the preanalytical, analytical and empirical areas is summarized. Next, the term of borderline for clinical practise is developed on the basis of characteristics and the global picture. Characteristics are: intensive, instable behaviour in relations, reduced control of impulse, disturbed affection and mood, psychotic manifestations, instable social adaptation. Diagnosis is founded on exploration of characteristics and on seizing of the global picture. The combination with other psychiatric disorders and separation from other personality disorders have to be considered with respect to differential diagnosis. The descriptive diagnosis has to be complemented from a psychodynamic point of view. The borderline patient has in his psychologic development failed to segregate sufficiently from his primary reference person. This results in a structural deficit and a weak ego. This latter is characterized by deficient integration and deficient separation, by disturbed perception of reality and by a non-specific general weakness of the ego. Finally, difficulties arising in the relations between physician and borderline patient are outlined.