Based on a nationwide survey of about 10,000 people in 185 government sponsored programs, this book assesses how far the mental health profession has moved beyond the traditional medical model, with its relatively closed doctor patient system, toward a broadly based public health intervention system. Encompassing various levels of mental health and disorder, this framework presents an approach which embraces prevention, treatment, and rehabilitation, and which entails coordinated planning with other community programs in health, education, and welfare. Attention is given to efforts to develop criteria for using both paid and volunteer nonprofessionals; types of projects and agencies; clientele groups served; and significant characteristics of nonprofessionals (including older adults, youth, minority groups, and persons with less than a high school education). Typical patterns of professional and nonprofessional work are also compared. Recruitment, training, and supervision are reviewed, followed by research findings on project goals and the extent of innovation. Evidence shows that nonprofessionals are providing valuable new services as well as taking on existing tasks. (LY)