Zung Self-Rating Anxiety Scale (ZRAS)
Also known as: ZRAS, Zung Anxiety, SAS
The Zung Self-Rating Anxiety Scale (ZRAS), also known as the Self-Rating Anxiety Scale (SAS), is a 20-item self-report measure of anxiety symptoms. Developed by William W. K. Zung in 1971, the ZRAS assesses psychological and somatic manifestations of anxiety in the past week. It is widely used for anxiety screening in primary care, general medical settings, and mental health research.
Key highlights
- Brief 20-item format enables rapid screening with minimal respondent burden
- Self-report administration makes it accessible and practical for busy primary care and general medical settings
- Validated across diverse medical and psychiatric populations with good internal consistency
- Simple scoring yields an interpretable anxiety index ranging from 25 to 100
Intuition
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How it works
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When to use it
The ZRAS is suitable for rapid anxiety screening in primary care, general medical settings, occupational health, and community mental health. It is less commonly used in specialist mental health than the Hamilton Anxiety Rating Scale (HAM-A) but remains valuable in primary care and general practice for case identification. The instrument is useful for baseline measurement and tracking anxiety change during treatment.
Strengths & limitations
- Brief 20-item format enables rapid screening with minimal respondent burden
- Self-report administration makes it accessible and practical for busy primary care and general medical settings
- Validated across diverse medical and psychiatric populations with good internal consistency
- Simple scoring yields an interpretable anxiety index ranging from 25 to 100
- Less widely used and researched than alternative anxiety measures (HAM-A, DASS-21), with smaller body of validation literature
- Self-report bias: individuals may minimize anxiety due to stigma or overestimate due to temporary stress
- Includes somatic items that may be elevated in medical illness independent of anxiety
Common pitfalls
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Applications
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Frequently asked
How is the ZRAS anxiety index calculated?
Sum all 20 items (with five items reverse-scored), then convert to a standardized anxiety index from 25 to 100 using the formula: (raw score / 80) × 75 + 25. Alternatively, some scoring methods use the simple raw score sum ranging from 20 to 80.
What is the difference between the ZRAS and the HAM-A?
The ZRAS is a self-report instrument, while the HAM-A is clinician-administered. The HAM-A is considered the gold standard in specialist mental health and research; the ZRAS is more practical in primary care. HAM-A is preferred when trained clinicians are available; ZRAS is preferred for efficiency in general practice.
Can the ZRAS be used in patients with medical illness?
The ZRAS can be used but with caution, as somatic symptoms in the scale may reflect medical conditions rather than anxiety. In medically ill populations, interpret elevated ZRAS scores within clinical context, considering concurrent medical symptoms and conditions.
Is the ZRAS sensitive to anxiety treatment effects?
Yes. The ZRAS is sensitive to antianxiety medication and psychotherapy effects. A reduction of 5–10 points on the anxiety index typically indicates meaningful improvement.
Sources
- 1.Zung, W. W. (1971). A rating instrument for anxiety disorders. Psychosomatics, 12(6), 371-379.
- 2.Dunstan, D. A., Scott, N., & Todd, A. K. (2005). Screening for anxiety and depression: Reassessing the utility of the Zung scales. BMC Psychiatry, 5, 8.
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Cite this page
ScholarGate. (2026, June 3). Zung Self-Rating Anxiety Scale. ScholarGate. https://scholargate.app/clinical-psychology/zung-anxiety-scale