Original Articles

Implications of modifying the duration requirement of generalized anxiety disorder in developed and developing countries

S. Lee^a1 c1, A. Tsang^a2, A. M. Ruscio^a3, J. M. Haro^a4, D. J. Stein^a5, J. Alonso^a6, M. C. Angermeyer^a7, E. J. Bromet^a8, K. Demyttenaere^a9, G. de Girolamo^a10, R. de Graaf^a11, O. Gureje^a12, N. Iwata^a13, E. G. Karam^a14, J.-P. Lepine^a15, D. Levinson^a16, M. E. Medina-Mora^a17, M. A. Oakley Browne^a18, J. Posada-Villa^a19 and R. C. Kessler^a20

^a1 Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong, PRC, USA

^a2 Hong Kong Mood Disorders Center, The Chinese University of Hong Kong, Hong Kong, PRC, USA

^a3 Department of Psychology, University of Pennsylvania, Philadelphia, USA

^a4 Sant Joan de Deu-SSM, Barcelona, Spain

^a5 University of Cape Town, UCT Department of Psychiatry, Cape Town, South Africa

^a6 Health Services Research Unit, IMIM-Hospital del mar, CIBER en Epidemiologia y Salud Publica (CIBERESP), Barcelona, Spain

^a7 Center for Public Mental Health, Gösing a.W, Austria

^a8 SUNY Stony Brook, Stony Brook, New York, NY, USA

^a9 University Hospital Gasthuisburg, Leuven, Belgium

^a10 Regional Health Care Agency, Emilia-Romanga Region, Italy

^a11 Netherlands Institute of Mental Health and Addiction, Utrecht, The Netherlands

^a12 Department of Psychiatry, University College Hospital, Ibadan, Nigeria

^a13 Hiroshima International University, Higashi-Hiroshima, Japan

^a14 Institute for Development, Research, Advocacy, and Applied Care (IDRAAC), St. George Hospital University Medical Center, Beirut, Lebanon

^a15 Hospital Fernand Widal, Paris, France

^a16 Ministry of Health, Mental Health Services, Jerusalem, Israel

^a17 National Institute of Psychiatry, Mexico City, Mexico

^a18 Department of Rural and Indigenous Health, School of Rural Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia

^a19 Colegio Mayor de Cundinamarca University, Bogotá, Colombia

^a20 Department of Health Care Policy, Harvard Medical School, Boston, USA

Abstract

Background A number of western studies have suggested that the 6-month duration requirement of generalized anxiety disorder (GAD) does not represent a critical threshold in terms of onset, course, or risk factors of the disorder. No study has examined the consequences of modifying the duration requirement across a wide range of correlates in both developed and developing countries.

Method Population surveys were carried out in seven developing and 10 developed countries using the WHO Composite International Diagnostic Interview (total sample=85 052). Prevalence and correlates of GAD were compared across mutually exclusive GAD subgroups defined by different minimum duration criteria.

Results Lifetime prevalence estimates for GAD lasting 1 month, 3 months, 6 months and 12 months were 7.5%, 5.2%, 4.1% and 3.0% for developed countries and 2.7%, 1.8%, 1.5% and 1.2% for developing countries, respectively. There was little difference between GAD of 6 months' duration and GAD of shorter durations (1–2 months, 3–5 months) in age of onset, symptom severity or persistence, co-morbidity or impairment. GAD lasting 12 months was the most severe, persistently symptomatic and impaired subgroup.

Conclusions In both developed and developing countries, the clinical profile of GAD is similar regardless of duration. The DSM-IV 6-month duration criterion excludes a large number of individuals who present with shorter generalized anxiety episodes which may be recurrent, impairing and contributory to treatment-seeking. Future iterations of the DSM and ICD should consider modifying the 6-month duration criterion so as to better capture the diversity of clinically salient anxiety presentations.

(Received July 16 2008)

(Revised September 26 2008)

(Accepted October 07 2008)

(Online publication December 18 2008)

Key Words:

• Cross-national;
• diagnosis;
• duration;
• epidemiology;
• generalized anxiety disorder

Correspondence:

^c1 Address for correspondence: Professor S. Lee, Director, Hong Kong Mood Disorders Center, 7A, Block E, Staff Quarters, Prince of Wales Hospital, Shatin, NT, Hong Kong. (Email: singlee@cuhk.edu.hk)