Zung Self-Rating Depression Scale (SDS)

The Zung Self-Rating Depression Scale (SDS) is a widely recognised, 20-item self-report instrument that quantifies the severity of depressive symptoms in…

Questions: 20
Duration: 5 min
Original title: Zung Self Rating Depression Scale
Adaptation: Zung Self-Rating Depression Scale (SDS)
Authors: William W.K. Zung
Created: 1965

The Zung Self-Rating Depression Scale (SDS) is a widely recognised, 20-item self-report instrument that quantifies the severity of depressive symptoms in adult populations. Developed to capture the pervasive affective, physiological, and cognitive dimensions of depression, it offers a robust measure of clinical presentation at a given moment in time.

As a validated, repeatable tool, the SDS provides clinicians with an objective metric to track symptom trajectories and assess treatment response over the course of care. By incorporating both positively and negatively worded statements, it minimises response bias and encourages careful reflection on recent functioning. This makes it a reliable instrument for complementing clinical interviews, giving structured insight into maladaptive patterns and allowing clinicians to distinguish temporary distress from entrenched states that might necessitate structured ACT for Depression interventions.

Example result

Fictitious result, computed from a sample set of answers.

Overall score

50/ 80

The Zung Self-Rating Depression Scale (SDS) is a 20-item self-report questionnaire designed to measure the severity of depressive symptoms. Developed by Dr. William W.K. Zung in 1965, it assesses the affective, cognitive, somatic, and psychomotor aspects of depression over the past few days.

20–40

Normal

41–47

Mild to Moderate

48–55

Moderate to Severe

56–80

Severe

Severity level descriptor provided by Zung.

For information

Cut-off≥ 40Clinically significant symptoms (Depression diagnosis)

Cut-off point recommended by Zung, showing high sensitivity but moderate specificity.

Dunstan et al. (2017)View the study ↗

Cut-off≥ 44Depression diagnosis (optimal revised cut-off)

Revised cut-off proposed by the authors to better balance sensitivity and specificity, making the scale comparable to the DASS.

Dunstan et al. (2017)View the study ↗

Scoring

Sum, total score from 20 to 80, each item is scored on a 4-point scale (from 1 to 4).

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What the test measures

The SDS evaluates the core clinical dimensions of a depressive episode, capturing the frequency of specific symptoms over the preceding days.

Affective symptoms: Probes pervasive sadness, crying spells, and loss of hope.
Physiological equivalents: Evaluates somatic shifts such as sleep disturbance, appetite changes, constipation, and unexplained fatigue.
Cognitive disturbances: Assesses impairments in clarity of thought, decision-making capacity, and the rigid self-judgments often seen in all-or-nothing thinking.
Psychomotor activities: Captures agitation, irritability, and anhedonia, highlighting shifts in daily engagement.

This measure is intended for use with adults presenting with suspected or diagnosed depressive disorders.

When and why to use it

Integrating the SDS into clinical practice allows for standardized tracking and structured symptom evaluation.

Intake baseline: Establishes a quantifiable starting point for symptom severity before initiating pharmacological or psychological support.
Symptom profiling: Helps identify predominant clusters, such as distinguishing somatic complaints from the rigid internal rules driving should statements.
Monitoring change: Provides a reliable metric to track progress, evaluate treatment efficacy, and adjust therapeutic approaches over time.
Targeting interventions: Flags critical items, such as profound anhedonia, which may indicate the immediate need for a structured activity menu to reverse behavioral withdrawal.
Identifying avoidance: Highlights secondary symptoms like agitation that may prompt the clinician to explore adaptive vs maladaptive coping mechanisms.

Utilising a validated score adds a layer of objective measurement over clinical impression alone, anchoring the diagnostic process and ensuring subtle shifts in functioning are not overlooked.

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The questions

Please read each statement carefully. For each one, select the option that best describes how often you have felt or behaved this way during the past several days.
1. I feel down and sad.
Assesses the presence of pervasive low mood and fundamental sadness.
- Rarely or never
- Sometimes
- Often
- Most of the time
2. Morning is when I feel the best.
Evaluates diurnal variation in mood, a classic indicator of melancholic features.
- Rarely or never
- Sometimes
- Often
- Most of the time
3. I cry or feel like crying.
Captures emotional lability and the overt expression of distress.
- Rarely or never
- Sometimes
- Often
- Most of the time
4. I have trouble sleeping at night.
Probes the presence of insomnia or nocturnal sleep disruptions.
- Rarely or never
- Sometimes
- Often
- Most of the time
5. I eat as much as I usually do.
Examines changes in appetite that often accompany depressive states.
- Rarely or never
- Sometimes
- Often
- Most of the time
6. I still enjoy sex.
Screens for diminished libido or loss of sexual interest.
- Rarely or never
- Sometimes
- Often
- Most of the time
7. I notice that I'm losing weight.
Identifies recent, unintentional weight loss linked to metabolic or appetite shifts.
- Rarely or never
- Sometimes
- Often
- Most of the time
8. I have problems with constipation.
Assesses gastrointestinal slowing and somatic distress.
- Rarely or never
- Sometimes
- Often
- Most of the time
9. My heart beats faster than usual.
Probes somatic anxiety or autonomic arousal commonly comorbid with depression.
- Rarely or never
- Sometimes
- Often
- Most of the time
10. I get tired for no reason.
Evaluates the presence of profound lethargy and unexplained physical exhaustion.
- Rarely or never
- Sometimes
- Often
- Most of the time
11. My mind is as clear as it usually is.
Captures self-reported cognitive slowing and diminished mental clarity.
- Rarely or never
- Sometimes
- Often
- Most of the time
12. I find it easy to do the things I used to do.
Assesses functional capacity and the ease of initiating routine tasks.
- Rarely or never
- Sometimes
- Often
- Most of the time
13. I am restless and can't keep still.
Identifies psychomotor agitation and the inability to remain physically calm.
- Rarely or never
- Sometimes
- Often
- Most of the time
14. I feel hopeful about the future.
Evaluates the patient's capacity for optimism versus pervasive hopelessness.
- Rarely or never
- Sometimes
- Often
- Most of the time
15. I am more irritable than usual.
Probes emotional reactivity and a decreased frustration tolerance threshold.
- Rarely or never
- Sometimes
- Often
- Most of the time
16. I find it easy to make decisions.
Examines executive functioning and the presence of severe indecisiveness.
- Rarely or never
- Sometimes
- Often
- Most of the time
17. I feel useful and needed.
Assesses the patient's sense of self-worth and social utility.
- Rarely or never
- Sometimes
- Often
- Most of the time
18. My life is pretty full.
Captures the subjective perception of a meaningful and engaged daily life.
- Rarely or never
- Sometimes
- Often
- Most of the time
19. I think others would be better off if I were dead.
Screens for passive suicidal ideation and feelings of being a burden to others.
- Rarely or never
- Sometimes
- Often
- Most of the time
20. I still enjoy the things I used to enjoy.
Evaluates the presence of anhedonia and the loss of pleasure in previously enjoyed activities.
- Rarely or never
- Sometimes
- Often
- Most of the time