The course and outcome of severe chronic illness are decisively affected by social and emotional variables. The conceptual approach of this article emphasizes an understanding of the individual, the family, and health care personnel as all facing a series of adaptive tasks in relation to the illness. Each of the three phases of the illness--the diagnostic, chronic, and end stage--poses special tasks and requires different defenses and coping capacities from the patient, family, and health care personnel. These are discussed as interdependent factors in a holistic framework.