Research Diagnostic Criteria and DSM-III

For several years the Research Diagnostic Criteria (RDC) have been used widely by investigators to select and describe research subjects. These criteria were used as the initial basis for the specified diagnostic criteria for the major diagnostic categories of DSM-III. With the availability of DSM-III in early 1980, research investigators involved in ongoing studies using the RDC and those planning future studies need to understand the relationship between these two systems so that they can make an informed decision about the use of these systems in their work. We compared each of the RDC categories with the corresponding DSM-III categories and determined major differences in the way the systems define many of the categories and the reasons form these differences. We delineated some of the issues that need to be considered when making decisions about which sets of criteria to use in research studies.