The concept of young adult chronic psychiatric patients: questions from a research perspective.

A recently labeled psychiatric service entity, young adult chronic patients ( YACPs ), is gaining widespread recognition in the professional and popular literature. This analytical overview of the literature demonstrates that the YACP concept has been useful as an ideal construct by which current deficits in the psychiatric service system may be assessed. As a research concept, however, it has serious conceptual and methodological limitations. Since the YACP concept is probably destined to remain with us, we must attempt to delineate rigorous demographic, diagnostic, and functional criteria for its use.