From a statistical standpoint, chronic illness is uncommon in adolescence. According to German, other European, and other international overviews, only about 10% of all adolescents are afflicted with a chronic illness. In the individual case, however, the onset of a chronic illness in adolescence can become a major stressor, which requires extraordinary coping efforts on the part of the adolescent. Similarly, the additional responsibilities involved in caring for a chronically ill adolescent may become a burden for the parents. Epidemiological surveys have shown that adolescents with a chronic illness are at significantly greater risk than their healthy peers for developing behavioral and emotional problems. Indeed, the onset and progression of a chronic illness exert many negative effects on the developmental processes occurring in adolescence. For example, chronic illness may jeopardize an adolescent's autonomous development, often to the point that he or she becomes fixed in the role of a child. All adolescents afflicted with a chronic illness, irrespective of severity and duration of the illness, must negotiate a delicate balance between adhering to the medical treatment regimen and following the normal course of developmental progression.

This book is largely based on the results of a longitudinal study of coping processes in chronically ill adolescents that I initiated and led at the University of Bonn, Germany. Although the study focused on one particular illness, juvenile diabetes, the findings are applicable to other chronic illnesses showing similar characteristics and long-term stress.