[Generalized anxiety disorder, now and the future: a perspective to the DSM-5].

: Generalized, persistent, and free-floating anxiety was first described by Freud in 1894. The diagnostic term generalized anxiety disorder (GAD) was not in classification systems until the publication of the diagnostic and statistical manual for mental disorders, third edition (DSM-III) in 1980. Initially considered as a residual category to be used when no other diagnosis could be made, it is not accepted that GAD represents a distinct diagnostic category yet. Since 1980, revisions to the diagnostic criteria for GAD in the DSM-III-R, DSM-IV and DSM-5 classifications have slightly redefined this disorder. The classification is fluid. The duration criterion has increased to 6 months in DSM-IV, but decreased to 3 months in DSM-5. This article reviews the development of diagnostic criteria for defining GAD from Freud to DSM-5 and compares the DSM-5 criterion with DSM-IV and the tenth revision of the International Classification of Disease. The impact of the changes in diagnostic criteria on research into GAD, and on diagnosis, differential diagnosis, will be discussed.