Description

The Zung Self-Rating Depression Scale (ZSDS) is a psychometric tool developed to assess depression. It was created by William W.K. Zung in 1965 and is widely used in clinical and research settings to measure the severity of depressive symptoms. Below is a detailed description of the scale’s objectives, analysis, and scoring, as well as relevant references.

Objective

The main goal of the Zung Self-Rating Depression Scale is to provide an easy-to-use and reliable method for the self-assessment of depressive symptoms. Specifically, the scale aims to:
Measure the severity of depressive symptoms.
Monitor changes in a patient’s condition over time.
Support the diagnosis of depression by clinical psychologists and psychiatrists.

Analysis

The Zung Self-Rating Depression Scale consists of 20 questions concerning symptoms observed in depression. These symptoms cover various categories, such as:
Emotional symptoms (e.g., feelings of sadness).
Cognitive symptoms (e.g., negative thoughts about the future).
Physical symptoms (e.g., sleep and appetite disturbances).
Impairments in social functioning.
The questions are answered on a 4-point Likert scale (1–4), where 1 represents “never” and 4 represents “almost always.”

Scoring

The total score ranges from 20 to 80. The scores are categorized as follows:
20–44: Normal range
45–59: Mild to moderate depression
60–69: Moderate to severe depression
70 and above: Severe depression
The scale’s scoring is based on statistical analyses that link scores to clinical diagnoses of depression.

References

Zung, W. W. K. (1965). A Self-Rating Depression Scale. Archives of General Psychiatry, 12(1), 63–70.
Zung, W. W. K. (1973). From art to science: The diagnosis and treatment of depression. Archives of General Psychiatry, 29(3), 328–337.
Shafer, A. (2006). Meta-analysis of the factor structures of four depression questionnaires: Beck, CES-D, Hamilton, and Zung. Journal of Clinical Psychology, 62(1), 123–146.