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Generalized anxiety disorder in adults: Epidemiology, pathogenesis, clinical manifestations, course, assessment, and diagnosis

David Baldwin, DM FRCPsych
Section Editor
Murray B Stein, MD, MPH
Deputy Editor
Richard Hermann, MD


Generalized anxiety disorder (GAD) is characterized by excessive and persistent worrying that is hard to control, causes significant distress or impairment, and occurs on more days than not for at least six months. Other features include psychological symptoms of anxiety, such as apprehensiveness and irritability, and physical (or somatic) symptoms of anxiety, such as increased fatigue and muscular tension.

Effective treatments for generalized anxiety disorder include psychological interventions such as cognitive-behavioral therapy and applied relaxation, and medications including selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors.

This topic addresses the epidemiology, pathogenesis, clinical manifestations, and diagnosis of generalized anxiety disorder. Pharmacotherapy and psychotherapy for generalized anxiety disorder are discussed separately. (See "Pharmacotherapy for generalized anxiety disorder in adults" and "Psychotherapy for generalized anxiety disorder in adults".)


Generalized anxiety disorder (GAD) is common in both community and clinical settings. Epidemiologic studies of nationally representative samples in the United States have found a lifetime prevalence of GAD of 5.1 percent [1,2] to 11.9 percent [3]. A review of epidemiological studies in Europe found a 12-month prevalence of 1.7 to 3.4 percent [4], and a lifetime prevalence of 4.3 to 5.9 percent [5].

GAD is one of the most common mental disorders in primary care settings and is associated with increased use of health services [6]. In a study of adult primary care patients in four Nordic countries, the rates of GAD were 4.1 to 6.0 percent among men, and 3.7 to 7.1 percent among women [7].


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Literature review current through: Sep 2016. | This topic last updated: Apr 12, 2016.
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