Psychological Medicine



Original Article

Should excessive worry be required for a diagnosis of generalized anxiety disorder? Results from the US National Comorbidity Survey Replication


AYELET MERON RUSCIO a1, MICHAEL LANE a1, PETER ROY-BYRNE a2, PAUL E. STANG a3, DAN J. STEIN a4, HANS-ULRICH WITTCHEN a5 and RONALD C. KESSLER a1c1
a1 Department of Health Care Policy, Harvard Medical School, Boston, MA, USA
a2 Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
a3 Galt Associates and Department of Health, College of Health Sciences, West Chester University, West Chester, PA, USA
a4 Department of Psychiatry, University of Cape Town, South Africa
a5 Institute for Clinical Psychology and Psychotherapy, Dresden University of Technology, Germany

Article author query
ruscio am   [PubMed][Google Scholar] 
lane m   [PubMed][Google Scholar] 
roy-byrne p   [PubMed][Google Scholar] 
stang pe   [PubMed][Google Scholar] 
stein dj   [PubMed][Google Scholar] 
wittchen hu   [PubMed][Google Scholar] 
kessler rc   [PubMed][Google Scholar] 

Abstract

Background. Excessive worry is required by DSM-IV, but not ICD-10, for a diagnosis of generalized anxiety disorder (GAD). No large-scale epidemiological study has ever examined the implications of this requirement for estimates of prevalence, severity, or correlates of GAD.

Method. Data were analyzed from the US National Comorbidity Survey Replication, a nationally representative, face-to-face survey of adults in the USA household population that was fielded in 2001–2003. DSM-IV GAD was assessed with Version 3.0 of the WHO Composite International Diagnostic Interview. Non-excessive worriers meeting all other DSM-IV criteria for GAD were compared with respondents who met full GAD criteria as well as with other survey respondents to consider the implications of removing the excessiveness requirement.

Results. The estimated lifetime prevalence of GAD increases by ~40% when the excessiveness requirement is removed. Excessive GAD begins earlier in life, has a more chronic course, and is associated with greater symptom severity and psychiatric co-morbidity than non-excessive GAD. However, non-excessive cases nonetheless evidence substantial persistence and impairment of GAD, high rates of treatment-seeking, and significantly elevated co-morbidity compared with respondents without GAD. Non-excessive cases also have sociodemographic characteristics and familial aggregation of GAD comparable to excessive cases.

Conclusions. Individuals who meet all criteria for GAD other than excessiveness have a somewhat milder presentation than those with excessive worry, yet resemble excessive worriers in a number of important ways. These findings challenge the validity of the excessiveness requirement and highlight the need for further research into the optimal definition of GAD.

(Published Online August 30 2005)


Correspondence:
c1 Department of Health Care Policy, Harvard Medical School, 180 Longwood Avenue, Boston, MA, USA 02115. (Email: kessler@hcp.med.harvard.edu)


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