This volume documents the knowledge currently available on the differential effectiveness of various psychotherapeutic procedures for 22 clinical pictures in psychology. At the same time, it attempts to build a bridge between clinical practice and research. The pathogenesis of all the disorders is dealt with in a way that takes all the different schools into account, thus providing a broad-based framework of knowledge and explanation for psychological disturbances in adults. The author provides a detailed overview of the current state of knowledge on the development and treatment of psychological disorders in children and young adults. Symptomatology, frequency of occurrence, different explanatory approaches, comorbidities, diagnostic procedures, interviewing and test procedures, treatment options and prospects for success are presented through a critical examination of evidence-based research. The author aims to provide all practising paediatric psychotherapists with a critical work in scientific methodology that allows them to evaluate the state of research on the various disorders in a nuanced but nevertheless comprehensible way.