Generalized Anxiety Disorder

Definition

Generalized anxiety disorder is characterized by excessive anxiety and worry about a variety of events or activities (e.g., work or school performance) that occurs more days than not, for at least 6 months. People with generalized anxiety disorder find it difficult to control their worry, which may cause impairment in social, occupational, or other areas of functioning.

Additional information about generalized anxiety disorder can be found on the NIMH Health Topics page on anxiety disorders.

Prevalence of Generalized Anxiety Disorder Among Adults

• Based on diagnostic interview data from National Comorbidity Survey Replication (NCS-R), Figure 1 shows past year prevalence of generalized anxiety disorder among U.S. adults aged 18 or older.¹
  • An estimated 2.7% of U.S. adults had generalized anxiety disorder in the past year.
  • Past year prevalence of generalized anxiety disorder among adults was higher for females (3.4%) than for males (1.9%).
• An estimated 5.7% of U.S. adults experience generalized anxiety disorder at some time in their lives.²

Figure 1

Generalized Anxiety Disorder with Impairment Among Adults

• Of adults with generalized anxiety disorder in the past year, degree of impairment ranged from mild to serious, as shown in Figure 2. Impairment was determined by scores on the Sheehan Disability Scale.³
• Impairment was distributed evenly among adults with generalized anxiety disorder. An estimated 32.3% had serious impairment, 44.6% had moderate impairment, and 23.1% had mild impairment.

Figure 2

Prevalence of Generalized Anxiety Disorder Among Adolescents

• Based on diagnostic interview data from National Comorbidity Survey Adolescent Supplement (NCS-A), Figure 3 shows lifetime prevalence of generalized anxiety disorder among U.S. adolescents aged 13-18.⁴
  • An estimated 2.2% of adolescents had generalized anxiety disorder, and an estimated 0.9% had severe impairment. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria were used to determine impairment.
  • The prevalence of generalized anxiety disorder among adolescents was higher for females (3.0%) than for males (1.5%).

Figure 3

Data Sources

Statistical Methods and Measurement Caveats

National Comorbidity Survey Replication (NCS-R)

Diagnostic Assessment and Population:

• The NCS-R is a nationally representative, face-to-face, household survey conducted between February 2001 and April 2003 with a response rate of 70.9%. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) mental disorders were assessed using a modified version of the fully structured World Health Organization Composite International Diagnostic Interview (WMH-CIDI), a fully structured lay-administered diagnostic interview that generates both International Classification of Diseases, 10^th Revision, and DSM-IV diagnoses. The DSM-IV criteria were used here. The Sheehan Disability Scale (SDS) assessed disability in work role performance, household maintenance, social life, and intimate relationships on a 0–10 scale. Participants for the main interview totaled 9,282 English-speaking, non-institutionalized, civilian respondents. Any anxiety disorder was assessed in a subsample of 5,692 adults. The NCS-R was led by Harvard University.
• Unlike the DSM-IV criteria used in the NCS-R and NCS-A, the current DSM-5 no longer places post-traumatic stress disorder or obsessive compulsive disorder in the anxiety disorder category. They are listed in new DSM5 categories.

Survey Non-response:

• In 2001-2002, non-response was 29.1% of primary respondents and 19.6% of secondary respondents.
• Reasons for non-response to interviewing include: refusal to participate (7.3% of primary, 6.3% of secondary); respondent was reluctant- too busy but did not refuse (17.7% of primary, 11.6% of secondary); circumstantial, such as intellectual developmental disability or overseas work assignment (2.0% of primary, 1.7% of secondary); and household units that were never contacted (2.0).
• For more information, see PMID: 15297905 .

National Comorbidity Survey Adolescent Supplement (NCS-A)

Diagnostic Assessment and Population:

• The NCS-A was carried out under a cooperative agreement sponsored by NIMH to meet a request from Congress to provide national data on the prevalence and correlates of mental disorders among U.S. youth. The NCS-A was a nationally representative, face-to-face survey of 10,123 adolescents aged 13 to 18 years in the continental United States. The survey was based on a dual-frame design that included 904 adolescent residents of the households that participated in the adult U.S. National Comorbidity Survey Replication and 9,244 adolescent students selected from a nationally representative sample of 320 schools. The survey was fielded between February 2001 and January 2004. DSM-IV mental disorders were assessed using a modified version of the fully structured World Health Organization Composite International Diagnostic Interview.

Survey Non-response:

• The overall adolescent non-response rate was 24.4%. This is made up of non-response rates of 14.1% in the household sample, 18.2% in the un-blinded school sample, and 77.7% in the blinded school sample. Non-response was largely due to refusal (21.3%), which in the household and un-blinded school samples came largely from parents rather than adolescents (72.3% and 81.0%, respectively). The refusals in the blinded school sample, in comparison, came almost entirely (98.1%) from parents failing to return the signed consent postcard.
• For more information, see PMID: 19507169  and the NIMH NCS-A study page.