Zung Self-Rating Anxiety Scale

The Self-Rating Anxiety Scale (SAS), developed by Professor Zung at Duke University School of Medicine in 1971, assesses anxiety severity and changes during treatment. Its 20 items cover emotional, physical, and psychomotor symptoms. It is used for rapid screening, severity assessment, treatment monitoring, and epidemiological surveys. Its simplicity and short completion time, about 5 minutes, have led to widespread use in clinical care, counseling, and research.

The SAS uses a 4-point scale (1–4) covering the past week. Multiply the raw total (20–80) by 1.25 to obtain a standardized score (25–100). Interpretation: <50 = normal range, 50–59 = mild anxiety, 60–69 = moderate anxiety, and ≥70 = severe anxiety. Five items—5, 9, 13, 17, and 19—describe calm states and are reverse-scored. A standardized score ≥50 suggests possible anxiety symptoms and a need for further professional assessment. Chinese norms give a general-population mean standardized score of approximately 29.78 ±10.07.

The SAS is intended for adults aged 18 and over with at least a junior secondary education. It suits community screening, initial counseling assessment, symptom monitoring in people with anxiety disorders, and research. It is unsuitable for people with severe cognitive impairment, those unable to understand items because of limited education, or those experiencing an acute psychotic episode. It can screen for symptoms across anxiety disorders, including generalized anxiety, panic, and social anxiety disorders.

Both are self-report scales developed by Zung, with similar structures but different content: SAS assesses anxiety and SDS assesses depression. Each has 20 items, a 4-point response scale, and a 1.25 conversion factor. They are often used together because anxiety and depression frequently co-occur, with comorbidity rates of 50–60%; combined results support differential assessment, a fuller picture of mood, and treatment planning. High scores on both may suggest a mixed anxiety–depression presentation requiring comprehensive treatment.

Five of the 20 SAS items—5, 9, 13, 17, and 19—describe calm or relaxed states, such as feeling that everything is fine or feeling calm. For these, selecting none or little of the time, normally scored 1, indicates greater anxiety. Scores are therefore reversed: 1 becomes 4, 2 becomes 3, 3 becomes 2, and 4 becomes 1. Reverse-keyed items help discourage mechanical responses, improve reliability and validity, and assess anxiety more accurately. The system reverses these scores automatically when calculating the total.

If your SAS standardized score is ≥50, consult a mental health professional. Particular concerns include a score ≥60 (moderate anxiety), significant physical symptoms such as rapid heartbeat, dizziness, breathing difficulty, or trembling without an identified physical cause, symptoms lasting more than 2 weeks and seriously affecting work or daily life, panic attacks, avoidance such as fear of leaving home or socializing, or recurrence of a previous anxiety disorder. Even within the normal score range, persistent tension, worry, or distress warrants support. The SAS is a screening tool, not a substitute for diagnosis; an anxiety diagnosis requires a comprehensive assessment by a psychiatrist or psychotherapist.