This paper is the final one in our series examining the DSM-IV diagnostic criteria for major depressive disorder. The data collected were part of the Rhode Island Methods to Improve Diagnostic Assessment and Services project, a unique integration of a research assessment protocol into a community-based clinical practice. We were able to examine a number of psychometric and conceptual issues in the diagnosis of depression because we modified the diagnostic interview to inquire about all diagnostic criteria, as well as additional associated features, of all patients. The results reported in the papers published earlier in the series suggested that some changes in the diagnostic criteria might be warranted. However, before changes are made to the diagnostic nomenclature, the results of any single study should be replicated. The cost of conducting this type of research is high, thereby reducing the likelihood of replication. As part of the Methods to Improve Diagnostic Assessment and Services project, we developed the Diagnostic Inventory for Depression (DID), a self-report scale that was specifically designed to assess the DSM-IV diagnostic criteria for major depressive disorder; thus, this scale could potentially be used to study many of the same questions examined in the present series, though at a fraction of the cost. In the present report, we used the DID to examine questions that were addressed in three of the prior reports in this series. The results of the present analysis based on the DID replicated the previously reported findings based on the SCID. This suggests that a self-report measure such as the DID could be used in other settings to examine the issues studied in the present series of papers, thereby facilitating the compilation of a more substantial literature upon which decisions regarding criteria modification could be based.