The epidemiology of generalized anxiety disorder

Generalized anxiety disorder is a commonly occurring disorder, with an estimated community epidemiologic study lifetime prevalence of 4% to 7% and estimated current prevalence of 1.5% to 3.0%. Generalized anxiety disorder is typically characterized by an early age of onset, a chronic course, and considerable role impairment. However, controversy has surrounded the diagnosis of generalized anxiety disorder since its introduction in DSM-III because of the extremely high comorbidity of generalized anxiety disorder with other mental disorders in clinical samples. This high comorbidity led critics to suggest that generalized anxiety disorder is better conceptualized as a prodrome, residual, or severity marker than as an independent disorder. However, several findings in epidemiologic and family studies argue against this view and suggest that generalized anxiety disorder is an important independent disorder that often causes significant impairment and substantial risk for secondary disorders. These findings and their implications for future research are reviewed.