Post-World War II
A much broader nomenclature was later developed by the U.S. Army (and modified by the Veterans Administration) in order to better incorporate the outpatient presentations of World War II servicemen and veterans (e.g., psychophysiological, personality, and acute disorders). Concurrently, the World Health Organization (WHO) published the sixth edition of International Classification of Diseases (ICD), which, for the first time, included a section for mental disorders. ICD-6 was heavily influenced by the Veterans Administration nomenclature and included 10 categories for psychoses and psychoneuroses and seven categories for disorders of character, behavior, and intelligence.
The American Psychiatric Association Committee on Nomenclature and Statistics developed a variant of the ICD-6 that was published in 1952 as the first edition of the Diagnostic and Statistical Manual: Mental Disorders (DSM-I). DSM-I contained a glossary of descriptions of the diagnostic categories and was the first official manual of mental disorders to focus on clinical utility. The use of the term “reaction” throughout DSM-I reflected the influence of Adolf Meyer's psychobiological view that mental disorders represented reactions of the personality to psychological, social, and biological factors.
In part because of the lack of widespread acceptance of the mental disorder taxonomy contained in ICD-6 and ICD-7, WHO sponsored a comprehensive review of diagnostic issues, which was conducted by the British psychiatrist Erwin Stengel. His report can be credited with having inspired many advances in diagnostic methodology--most especially the need for explicit definitions of disorders as a means of promoting reliable clinical diagnoses. However, the next round of diagnostic revisions, which led to DSM-II and ICD-8, did not follow Stengel's recommendations to any great degree. DSM-II was similar to DSM-I but eliminated the term “reaction.”