In children and young adults with psychosomatic conditions, the ?body&mind interface= is often so impaired that their body language is no longer comprehensible. A holistic assessment of a psychosomatic problem not only includes a careful somatic examination, but also involves understanding each patient=s social influences, inner mental and internal family psychological structures and dynamics, as well as interactions between these different perspectives. In addition, it is necessary to assess whether the intrapsychic and interpersonal resources in the situation are sufficient to allow physical, mental and social development in the existing environment. This book therefore endeavours to present the disease phenomena described from the point of view of developmental biology and developmental psychology.