The Psychiatric Status Schedule for epidemiological research. Methodological considerations.

The Psychiatric Status Schedule (PSS) was designed to improve the research value of clinical judgments in the assessment of psychopathology. Although constructed with data from psychiatric patients, it is also intended for use in case finding, as in epidemiological studies of the general population. Its usefulness for this purpose has been questioned on the basis of the low internal consistency of many of the PSS scales in a general population sample and strata thereof. We challenged this methodological stance. Using the same data set, the PSS can be shown to have validity for epidemiological use, in that it discriminates outpatients from the general population and identifies psychiatric "cases" variously defined.