Generalized anxiety disorder.

Since its inception as a diagnostic category in 1980, the definitional criteria for generalized anxiety disorder (GAD) have been revised substantially in each edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM). In DSM-III (American Psychiatric Association, 1980), GAD was a residual category (i.e., diagnosis was permitted only if criteria were not met for any other Axis I disorder); it was defined as the presence of generalized, persistent anxiety (continuous for a period of at least 1 month) as manifested by symptoms from at least three of four categories: (1) motor tension (e.g., muscle aches, GENERALIZED ANXIETY DISORDER Timothy A. Brown Tracy A. O’Leary David H. Barlow