T HIS special issue of the Journal of Health and Social Behavior focuses upon the Sociology of Mental Illness. The four sub-areas of the Sociology of Mental Illness operationalized for investigation within this issue were (1) estimates of the incidence and prevalence of mental illness in socioculturally defined populations; (2) investigations of sociocultural and social-psychological factors in the etiology of mental illness; (3) studies describing patterns of response by ill persons to their disorders, or those investigating sociocultural and social-psychological influences upon such responses; and (4) studies describing the responses of others (e.g., primary group members, psychiatrists, and public agencies) to the mentally ill, or those investigating sociocultural and social-psychological influences upon the nature of others' responses to mental illness. Four scholars widely acknowledged as experts within their particular fields were invited to submit papers dealing with recent developments in each sub-area. Thus, within this issue, Leo Srole, in considering the estimation of incidence and prevalence of mental disorder, describes changes in socio-psychiatric epidemiology he views as being in process since World War I I. The Midtown Manhattan Stuidy and the restudy of this population twenty years later are treated as a case history reflecting these changes. He also presents the first report of findings from his restudy. These findings include comparisons of the distributions of mental health ratings in the years 1954 and 1974 both for the total populations and for the respondent sub-cohorts 40-59 years of age in 1954 and 1974. Bi-rice Dohrenwend considers the etiological significance of sociocultural and social-psychological factors in the occurrence and distribution of functional psychiatric disorders through an examination of three bodies of evidence: (1) epidemiological studies of the true prevalence of psychiatric disorders; (2) literature dealing with individual reactions to extreme situations; and (3) investigations of relationships between psychopathology and more ordinary stressful life events. He aids our increasing understanding of the role of sociocultural and socialpsychological factors in the development of mental disorders by offering suggestions about the identification of quasiexperimental strategies, the adoption of unusual sampling plans, and the employment of prospective research designs. David Mechanic places the area of personal responses to psychological disorder within the broader context of the study of social selection, an aspect of sociological theory. He reviews four types of studies through which investigators seek understanding of the processes of individual responses to symptoms and select pathways for care, and considers methodological problems in executing studies about factors affecting personal responses to mental illness. He also evaluates the state of the relevant literature, and provides a frame of reference as a point of departure for further research. In the final paper, John Clausen and Carol Huffine offer a number of generalizations about social responses to mental illness. Those generalizations were based upon considerations of historical and anthropological evidence alnd of findings from systematic studies about fac-