This book is unique in two ways: it contains the first description of a consistently structured model of inpatient system therapy and simultaneously the first comprehensive presentation of a concept for inpatient child and adolescent psychiatry. This "Viersen Model" has proven itself in the everyday practice of many institutions in residential youth assistance as well as in child and adolescent psychiatry and psychotherapy. Wilhelm Rotthaus first provides a brief historical overview of the development of family therapy, outlines the fundamental principles of a constructivist system theory, and sketches the design of a systemic concept of humanity. On this basis, he elaborates on important characteristics of systemic therapy. By incorporating literature on the two focal topics of system therapy and inpatient psychotherapy, he achieves a theoretically grounded approach.