The 1908 publication of "A Mind That Found Itself" by Clifford Beers initiated the mental hygiene movement and a concern for the prevention of mental disorders. Primary prevention movements of the early 1900's recognized the need to deinstitutionalize mental health by bringing services and intervention to the community, recognized the influences of environmental and societal factors, and focused on the young as targets for intervention. The Child Guidance Movement grew and child guidance clinics proliferated. The eugenics movement advocated the prohibition of marriages between the handicapped, the feeble-minded, and between cousins in efforts to prevent insanity, and twentieth century writers have suggested combining eugenics with mental hygiene principles. The federal government became officially involved in prevention in 1930, and the National Mental Health Act was passed in 1946. Studies in the 1950's explored the relationship of environmental factors to mental disorders; the literature on primary prevention expanded in the 1960's and 1970's. A critical sense emerged and standards began to be questioned. A cyclical interest in prevention has occurred throughout the century and progress has been hindered by several recurrent and interacting factors. Contemporary researchers need to establish and follow consistent evaluation strategies. (NRB)