Overview
PHQ-9 (Patient Health Questionnaire-9) is one of the most widely used and clinically validated tools for screening, diagnosing, and monitoring depression severity.
Developed for use in primary care and mental health settings, PHQ-9 helps clinicians quickly identify depressive symptoms, assess severity, and track changes over time.
It is simple, reliable, and evidence-based — making it a cornerstone assessment in outcome-focused care.
What Does PHQ-9 Measure?
The PHQ-9 measures the frequency and severity of depressive symptoms over the past two weeks, aligned with the diagnostic criteria for Major Depressive Disorder (DSM).
It assesses symptoms such as:
- Low mood or hopelessness
- Loss of interest or pleasure
- Fatigue or low energy
- Sleep disturbances
- Appetite changes
- Difficulty concentrating
- Feelings of worthlessness or guilt
- Psychomotor changes
- Thoughts of self-harm or suicide
Who Is PHQ-9 For?
The PHQ-9 is suitable for:
- Adults (18+)
- Adolescents (with clinical judgment)
It is commonly used by:
- Psychologists
- Psychiatrists
- Therapists and counselors
- Primary care providers
- Mental health clinics and community services
- Digital mental health platforms
How PHQ-9 Is Scored
Each of the 9 items is rated on a 4-point scale based on symptom frequency:
- 0 – Not at all
- 1 – Several days
- 2 – More than half the days
- 3 – Nearly every day
Total Score Range
- Minimum score: 0
- Maximum score: 27
How PHQ-9 Is Used
PHQ-9 can be used at multiple points in care to support clinical decision-making.
Common use cases include:
- Initial depression screening
- Supporting diagnostic assessment
- Monitoring symptom severity over time
- Evaluating treatment effectiveness
- Measuring outcomes for supervision or reporting
It can be administered:
- At intake
- Periodically during treatment
- At discharge or follow-up
Interpreting PHQ-9 Scores
PHQ-9 scores correspond to anxiety severity levels:
- 0–4: Minimal or no depression
- 5–9: Mild depression
- 10–14: Moderate depression
- 15–19: Moderately severe depression
- 20–27: Severe depression
Higher scores indicate greater symptom severity and may signal the need for clinical intervention.
Using PHQ-9 on Our Platform
When administered through our platform, PHQ-9 enables you to:
- Collect responses digitally and securely
- Track score changes over time
- Visualize progress through charts and reports
- Combine PHQ-9 data with other assessments
- Share clear, easy-to-understand insights with clients and supervisors
This makes outcome measurement seamless — without adding administrative burden.
Clinical Considerations
- PHQ-9 is a screening and monitoring tool, not a standalone diagnostic instrument
- Item 9 (self-harm thoughts) should always be reviewed carefully and followed up clinically
- Results should be interpreted in the context of clinical judgment and additional assessment
Kroenke, K., Spitzer, R. L., & Williams, J. B. (2001).
PHQ-9: Validity of a brief depression severity measure.
Journal of General Internal Medicine, 16, 606–613.
Kroenke, K., Spitzer, R. L., & Williams, J. B. (2002).
PHQ-9: A new depression diagnostic and severity measure.
Psychiatric Annals, 32, 509–521.
Kroenke, K., Spitzer, R. L., & Williams, J. B. (2003).
The Patient Health Questionnaire-2: Validity of a two-item depression screener.
Medical Care, 41, 1284–1292.
It measures the severity of depressive symptoms based on DSM criteria.
It is typically completed by adults and adolescents as a self-report measure.
Most clients complete it in under 5 minutes.
Higher scores suggest greater severity of depressive symptoms.
It is commonly used at intake and repeated regularly to monitor progress.
It is a screening and monitoring tool, not a standalone diagnostic instrument.
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