Interestingly, the first official psychiatric classification system was developed to help with the U.S. Census. The Census Bureau aimed for an accurate estimation of the U.S. population, including residents of mental hospitals. In 1840, the U.S. Census had only one category for mental illness, idiocy/insanity. By 1880, there were seven categories: mania, melancholia, monomania, paresis, dementia, dipsomania, and epilepsy. In 1917, the official psychiatric professional associations decided it was time to design their own classification system, taking the diagnosis of mental illness out of the hands of the government.

What would soon become the American Psychiatric Association (APA) joined with the National Commission on Mental Hygiene to develop a nomenclature (system of labels) for mental disorders. This system applied mainly to the most severely ill inpa-tients, those living in mental hospitals. After World War II brought back veterans suffering from the psychological aftereffects of war, the diagnostic systems were expanded to consider the needs of outpatients, those living in the community. The first edition of the DSM was published in 1952, DSM-III came in 1980, DSM-III-R in 1987, and DSM-IV in 1994. The projected publication date of DSM-V is 2013.