Defining chronic mental illness: a concept paper.

Three criteria--diagnosis, duration, and disability--are gaining currency in efforts throughout the United States to define the concept of chronic mental illness in a precise manner. However, there is presently no consensus on the specific character or relative importance of these criteria. Nor is there consensus on the nature of the interrelationships among these elements. These conceptual concerns must be resolved if uniformity in service planning and research on the chronic mentally ill is to be achieved.