About the Generalized Anxiety Disorder 7-item scale
GAD-7, 2006
Primary source
Spitzer RL, Kroenke K, Williams JBW, Löwe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006;166(10):1092-1097.
Who it was built on
Developed in 15 primary care clinics in the United States on 2,740 adult patients (Spitzer and colleagues, 2006).
Source and attribution
- Developed by
- Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc.
- Published
- Archives of Internal Medicine, 22 May 2006
- Rights
- Free to reproduce, display and translate, as stated by its developers on the questionnaire. The questions are used unchanged.
The score is calculated exactly as published in the scale.
How well it works
In the original study the scale identified 89% of people with generalized anxiety disorder (sensitivity) and correctly cleared 82% of people without it (specificity). Its authors define four symptom levels, minimal to severe, and recommend a fuller assessment from the moderate level.
Limitations
A measure of symptom severity over two weeks, not a diagnosis. Studies in India (Kerala, 2021) found the questionnaire behaves as in Western samples but did not measure how accurately it detects an anxiety disorder there, so no Indian accuracy figure is given. The Hindi questions are the official translation for India.
Other sources used
The question about difficulty in daily life comes from the same family of questionnaires and is not part of the score.
PHQ and GAD-7 instruction manual, phqscreeners.com