Zung Self-Rating Anxiety Scale SAS
Zung Self-Rating Anxiety Scale SAS overview
Creator and Context
The Zung Self-Rating Anxiety Scale (SAS) is a 20 item self report measure of anxiety, published by William Zung in 1971 as the companion to his depression scale.
Like the SDS, it uses two different scores: a raw score and a converted index score. Confusing the two is the single most common error made with this instrument.
Presenting Conditions
The 20 items cover affective and somatic symptoms of anxiety, with the content weighted heavily towards the somatic. Some items are positively worded and reverse scored.
There are no formal subscales.
Administration
Self administered in about five minutes. Each item is rated from None, or a little of the time (1) to Most, or all of the time (4), in relation to the past several days.
Desired Audience
Adults, for screening anxiety symptoms and grading their severity.
The Zung SAS pairs directly with the SDS, on the same scoring logic and the same response format. For services running both, that consistency has practical value, and there is a long comparative literature behind both.
Considerations
The raw versus index confusion is the defining hazard. A review found that up to 45 percent of papers using an SAS cut off had incorrectly applied index criteria to raw scores. Applying the index bands to a raw score materially under identifies cases.
The item content is heavily somatic, which risks false positives in medically ill populations.
The 1971 norms are dated, and in most modern practice the SAS has been superseded by measures such as the GAD-7 and the DASS.
Copyright status is not clearly documented. Confirm before commercial deployment.
It is a screening instrument, not a diagnosis.
How to score the Zung Self-Rating Anxiety Scale SAS
Conducting the assessment
The person rates 20 items from 1 to 4 for the past several days. Positively worded items are reverse scored.
Interpretation
Items are summed to give a raw score from 20 to 80, which is converted to an index score by multiplying by 1.25, giving a range of 25 to 100.
The severity bands apply to the index score:
Below 45 normal
45 to 59 mild to moderate anxiety
60 to 74 marked to severe
75 to 100 extreme
An index of 45 corresponds to a raw score of 36. Contemporary evidence (Dunstan and Scott, 2020) suggests a raw score of 36 may be appropriate for clinical screening, while the original raw cut off of 40 is more appropriate for research use.
Clinical Considerations
Be explicit about whether you are displaying a raw or an index score. This is the error to design out.
Consider the physical health picture. The somatic loading will over identify anxiety in medically unwell people.
Where a contemporary measure is acceptable, the GAD-7 is a simpler and better validated option.
Zung Self-Rating Anxiety Scale SAS use cases
Screening for anxiety symptoms in adults
Grading anxiety severity
Use alongside the Zung SDS where consistency across the pair is wanted
Research
Category
Anxiety
Research Summary
Zung, W. W. K. (1971). A rating instrument for anxiety disorders. Psychosomatics, 12(6), 371 to 379.
Dunstan, D. A., & Scott, N. (2020). Norms for Zung's Self-rating Anxiety Scale. BMC Psychiatry, 20, 90.
Dunstan, D. A., Scott, N., & Todd, A. K. (2017). Screening for anxiety and depression: Reassessing the utility of the Zung scales. BMC Psychiatry, 17, 329.
Other Assessment Guides
Clinical Outcomes in Routine Evaluation 10 CORE-10
Explore the Clinical Outcomes in Routine Evaluation 10 (CORE-10), an efficient tool for assessing and monitoring psychological distress. Ideal for clinicians and researchers, this guide covers its use in screening, tracking treatment progress, and evaluating therapy effectiveness.
Depression Anxiety Stress Scales DASS-21
Explore the Depression Anxiety Stress Scales (DASS-21) in our comprehensive guide. Learn about its creation, use in assessing emotional states, practical application, scoring, and clinical guidance. Ideal for professionals seeking a detailed understanding of DASS-21's role in mental health assessment
Generalized Anxiety Disorder 7 Item Scale GAD-7
Explore the Generalized Anxiety Disorder 7 Item Scale (GAD-7), a vital tool for screening and measuring anxiety severity. Our guide covers its use, scoring system, and clinical implications, ideal for healthcare professionals and researchers in mental health.
Note on Assessment licensing
Some assessments are copyright protected and require a licence or the copyright holder's permission for clinical, commercial or digital use. Where that applies, obtaining and maintaining that permission is the responsibility of the practice or organisation using the assessment. Tacklit provides the digital administration, scoring and reporting. We do not grant, transfer or supply rights to the underlying instrument.
