Psychological Medicine

Rethinking the duration requirement for generalized anxiety disorder: evidence from the National Comorbidity Survey Replication 1

a1 Department of Health Care Policy, Harvard Medical School, Boston, MA, USA
a2 Pfizer, Inc., New York, NY, USA
a3 Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
a4 Department of Public Health, West Chester University, and Galt Associates, Blue Bell, PA, USA
a5 Department of Psychiatry, University of Stellenbosch, Cape Town, South Africa
a6 Institute of Clinical Psychology and Psychotherapy, Technical University of Dresden, Dresden, Germany

Article author query
kessler rc   [PubMed][Google Scholar] 
brandenburg n   [PubMed][Google Scholar] 
lane m   [PubMed][Google Scholar] 
roy-byrne p   [PubMed][Google Scholar] 
stang pd   [PubMed][Google Scholar] 
stein dj   [PubMed][Google Scholar] 
wittchen hu   [PubMed][Google Scholar] 


Background. The proposed revisions of the ICD and DSM diagnostic systems have led to increased interest in evaluation of diagnostic criteria. This report focuses on the DSM-IV requirement that episodes of generalized anxiety disorder (GAD) must persist for at least 6 months. Community epidemiological data are used to study the implications of changing this requirement in the range 1–12 months for estimates of prevalence, onset, course, impairment, co-morbidity, associations with parental GAD, and sociodemographic correlates.

Method. Data come from the US National Comorbidity Survey Replication (NCS-R), a US household survey carried out during 2001–2003. Version 3.0 of the WHO Composite International Diagnostic Interview (WMH-CIDI) was used to assess DSM-IV anxiety disorders, mood disorders, substance disorders, and impulse-control disorders.

Results. Lifetime, 12-month, and 30-day prevalence estimates of DSM-IV GAD changed from 6·1%, 2·9%, and 1·8% to 4·2–12·7%, 2·2–5·5%, and 1·6–2·6% when the duration requirement was changed from 6 months to 1–12 months. Cases with episodes of 1–5 months did not differ greatly from those with episodes of [gt-or-equal, slanted]6 months in onset, persistence, impairment, co-morbidity, parental GAD, or sociodemographic correlates.

Conclusions. A large number of people suffer from a GAD-like syndrome with episodes of <6 months duration. Little basis for excluding these people from a diagnosis is found in the associations examined here.

(Published Online March 14 2005)

c1 Department of Health Care Policy, Harvard Medical School, 180 Longwood Avenue, Boston, MA, USA 02115. (Email:


1 The views and opinions expressed in this report are those of the authors and should not be construed to represent the views of any of the sponsoring organizations, agencies, or U.S. Government.