Nomenclature and Classification are a part of standard psychiatric practice.
They serve as useful index tabs, and are necessary for statistical or administrative purposes.
A Nosology of mental disorders was already in use by the time of Hippocrates and Galen. Nowadays we have two important classification :
1º)- The DSM (Diagnostic an Statistical Manual of the American Psychiatric Association). It goes now for number four.
2º)- The ICD , the International Classifications of Diseases publishes by the World Health Organization. It intended to supply a common basis for interconversion of various other systems. Nowadays it goes for number ten.
A general rule say that a medical classification last about a decade.
(Edited by Dra. Moya Guirao)