The relationship between social level and psychiatric disorders has been explored by a a demographic study of patients (i. e., patients in professional contact with psychiatrists) in metropolitan New Haven, and by a background study of the stratification of a sample of the general population in the same community. Significant relationships have been found between social level and (1) prevalence of psychiatric patients according to our definition, (2) types of psychiatric disorders in the patient population, and (3) types of therapy. Our data throw some light on social stratification in current psychiatric practice; they suggest the existence of an uneven social class distribution of psychoses in the general population. The project will continue, by sociological, psychiatric, and psychological techniques, to gather facts and to explore the meaning of the preliminary findings reported in this paper. Only a study of incidence and prevalence of psychiatric disorders in the general population will solve some of the basic problems posed.Abstract Teaser