Zung Self-Rating Depression Scale – ZUNG
A 20-item self-administered survey used to quantify the depressive status of adult patients.
Scale Development & Technical Details
Scale Overview
The Zung Self-Rating Depression Scale – ZUNG was developed by William W.K. Zung (1965). It is designed to measure Depression. The scale is intended for use with Adults.
Scale Structure
This instrument consists of 20 items organized into 4 factors/subscales: Core Depressive Factor, Cognitive Factor, Anxiety Factor, Somatic Factor.
| Factor / Subscale | Items | N |
|---|---|---|
| Core Depressive Factor | 1,3,6,14,17,18,19,20 | 8 |
| Cognitive Factor | 10,11,12,16 | 4 |
| Anxiety Factor | 4,13,15 | 3 |
| Somatic Factor | 5,7,9 | 3 |
Response Format
Respondents rate each item using a custom response format.
Response anchors: 1 = A little of the time, 2 = Some of the time, 3 = Good part of the time, 4 = Most of the time.
The scale includes 10 reverse-scored items to reduce acquiescence bias.
Scoring
Items are scored by subscale, with each subscale sum representing a distinct dimension.
Total scores range from 20 to 80. Interpretation guidelines:
- Normal Range: 20 – 49
- Mildly Depressed: 50 – 59
- Moderately Depressed: 60 – 69
- Severely Depressed: 70 – 80
Psychometric Properties
Internal Consistency: The scale has demonstrated good to excellent internal consistency with reported Cronbach’s alpha values of Cronbach's alpha of 0.79, split-half reliability of 0.73.
Administration
The scale is self-administered and typically takes approximately 5 minutes to complete. It can be administered individually or in group settings. No special training is required for administration.