Adolescents with pronounced borderline symptoms have a high risk of developing a borderline personality disorder. Therefore, early treatment is important. The therapy for borderline disorders in adolescence presented in this book is based on the psychoanalytical-interactional method (PIM). The focus of the treatment is on the patient's difficulties in regulating themselves and their interpersonal relationships. Initially, the authors address the characteristics of borderline disorders. They also consider the combined disorder of social behavior and emotions, which can be seen as a precursor to borderline personality disorder. The subsequent chapters introduce models of development and the diagnostic approach. The treatment principles of PIM are then explained in detail. A central characteristic.