Abstract
DSM-IV is the standard language for psychiatric diagnosis in the United States. An unanticipated consequence of DSM-III is international interest in this American document; for example, DSM-III was translated into 13 languages. This was due to its adopting a descriptive classification that eschewed etiologic theory and contained operational definitions, following Stengel’s recommendations in his WHO report in 1959. These principles were eventually implemented in ICD-10, with the result of being two somewhat different classification systems. Although WHO-APA collaborations have minimized differences, a significant number remains, with only a few reflecting true ideological differences. The challenge for the future will be to integrate the two systems to produce, as much as possible, a unified system for international diagnostic communication.