Depression Self‑Assessment (PHQ-9)

The Patient Health Questionnaire‑9 (PHQ‑9) is a widely used, evidence‑based screening tool for depression severity. Answer nine questions about the past two weeks, receive your total score, severity level, and personalized guidance.

Please select the option that best describes how often you have been bothered by each problem over the last 2 weeks.
? Minimal symptoms (score 1–4)
? Moderate depression (score ~12)
⚠️ Severe pattern (score >20)
Privacy assured: All responses are processed locally in your browser. No data is transmitted or stored.

Understanding the PHQ‑9: A Gold‑Standard Depression Screener

The Patient Health Questionnaire‑9 (PHQ‑9) is a multipurpose instrument for screening, diagnosing, monitoring, and measuring the severity of depression. Developed by Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke, and colleagues, it aligns with DSM‑5 diagnostic criteria for major depressive disorder. Its brevity and high validity have made it the most widely used depression scale in primary care and mental health research.

Clinical Scoring Guidelines:
  • 0–4: Minimal depression – self‑care, watchful waiting
  • 5–9: Mild depression – consider support, brief counseling
  • 10–14: Moderate depression – treatment plan (therapy or medication)
  • 15–19: Moderately severe – active treatment recommended
  • 20–27: Severe depression – immediate clinical evaluation
Source: Kroenke K, Spitzer RL, Williams JB. The PHQ‑9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606‑613.
Recommended by leading health authorities:

The US Preventive Services Task Force (USPSTF) recommends screening for depression in adults, including pregnant and postpartum persons, with adequate systems in place to ensure accurate diagnosis, effective treatment, and appropriate follow‑up. (USPSTF Grade B, 2023)

The National Institute for Health and Care Excellence (NICE) guidelines [NG222] endorse the PHQ‑9 as a validated tool for case‑finding and monitoring depression in adults.

Why Use This Assessment?

Early recognition of depressive symptoms improves outcomes. The PHQ‑9 helps individuals reflect on their emotional wellbeing and facilitates productive conversations with clinicians. Its high test‑retest reliability and sensitivity make it a standard tool in both research and practice. This interactive version provides instant scoring, severity classification, and actionable guidance while respecting your privacy.

Each item is scored from 0 ("not at all") to 3 ("nearly every day"). The total score (0–27) guides clinical decision‑making. A score ≥10 is often used as a cutoff for probable major depression, though clinical judgment remains essential.

How to Take the Assessment

  1. Read each question carefully.
  2. Select the response that best describes how often you experienced the symptom over the past 2 weeks.
  3. Answer all nine items to obtain an accurate total score.
  4. Click "Calculate Score & Severity" to view your results.
  5. Use the example buttons to understand typical response patterns for different severity levels (educational only).

Clinical Validity & Reliability

The PHQ‑9 has been extensively validated across diverse populations. A meta‑analysis by Moriarty et al. (2015) found strong internal consistency (α = 0.86–0.89) and criterion validity compared to structured diagnostic interviews. It is recommended by the National Institute for Health and Care Excellence (NICE), the US Preventive Services Task Force (USPSTF), and the American Psychological Association for depression screening in adults.

Tool accuracy & equivalence: Digital administration of the PHQ‑9 has been shown to produce scores equivalent to paper‑based versions. A 2010 study in the Journal of Medical Internet Research (doi:10.2196/jmir.1190) confirmed that electronic and paper PHQ‑9 scores are highly correlated (r = 0.94). This calculator implements the original scoring algorithm exactly as published.
Severity Level Score Range Typical Clinical Action
Minimal 0–4 Self‑management, follow‑up as needed
Mild 5–9 Watchful waiting, supportive counseling
Moderate 10–14 Psychotherapy, possible pharmacotherapy
Moderately Severe 15–19 Active treatment (therapy +/‑ medication)
Severe 20–27 Immediate clinical evaluation, intensive treatment
Evidence in Practice: Primary Care Integration

A 2022 study in the Journal of Affective Disorders reported that routine PHQ‑9 screening in primary care increased depression detection rates by 43% and improved treatment engagement. Self‑administered digital versions maintain equivalent accuracy to paper‑based formats, making this tool a reliable proxy for clinical screening when followed by professional assessment.

Cultural Considerations & Limitations

While the PHQ‑9 is widely validated, cultural factors may influence symptom expression and reporting. Some populations may express distress somatically, and certain items (e.g., appetite changes) may be interpreted differently across cultures. The PHQ‑9 is a screening tool, not a diagnostic instrument; it does not replace a comprehensive clinical interview. A positive screen should always be followed by a professional evaluation that considers individual context, medical history, and cultural background.

Frequently Asked Questions

No. The PHQ‑9 is a screening tool that quantifies symptom severity. Only a licensed mental health professional can diagnose depression after a comprehensive evaluation, including clinical interview and consideration of other factors.

If your score indicates moderate to severe depression, we strongly encourage you to reach out to a primary care provider, therapist, or counselor. If you have thoughts of self‑harm, contact emergency services or a crisis line immediately. You are not alone – help is available 24/7.

Yes. You may retake it anytime to track changes in symptoms. However, meaningful clinical monitoring should be done in collaboration with a healthcare professional.

Yes, the PHQ‑9 is in the public domain and can be used without permission. We provide it for educational purposes with proper attribution to the original authors.

When implemented correctly, digital PHQ‑9 tools produce the same score as paper versions. Our calculator uses the standard scoring algorithm, ensuring accuracy. However, interpretation should always involve a healthcare provider.

Based on published research – This tool implements the PHQ‑9 as described in the original 2001 paper by Kroenke et al. (J Gen Intern Med). Scoring and severity thresholds follow the validated guidelines. For clinical use, please refer to the original literature and consult a healthcare professional.

References: MDCalc PHQ‑9; Kroenke K, Spitzer RL, Williams JB. J Gen Intern Med. 2001; APA PHQ‑9 information; USPSTF Depression Screening Recommendation.