Mental illnesses provide a difficult set of challenges to American health and social institutions. Those challenges have been a continuous concern of David Mechanic's over the course of his career. In this article we trace the development of modern economic and organizational structures that drive the delivery of mental health care in the early part of the twenty-first century. We show how the nature of mental disorders themselves and the treatment for addressing those illnesses pose fundamental difficulties to health care organizational and financing structures. We analyze the factors that have caused the dramatic changes in how American society has addressed mental illnesses over the past fifty years. Specifically, we note the central influence that mainstream health, income support, and disability programs have had in shaping mental health care. We argue that the interaction of the unique features of mental illnesses and changes in mainstream health and social policy led mental health care to evolve so differently from general medical care.