PHQ-9 Depression Screening
Patient Health Questionnaire-9 · Also known as: PHQ-9, depression screening scale
The Patient Health Questionnaire-9 (PHQ-9) is a brief, 9-item self-report instrument for screening and measuring the severity of depressive symptoms in primary care and mental health settings. Developed by Kurt Kroenke and colleagues in 2001, the PHQ-9 is now widely used in healthcare systems worldwide as a rapid, accurate screening and monitoring tool.
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When to use it
The PHQ-9 is appropriate for screening in primary care settings, mental health clinics, and research. It is especially useful for rapid assessment of depression severity, monitoring treatment response, and identifying patients requiring more intensive evaluation or treatment. The tool is less reliable in severe cognitive impairment, non-English speakers, and complex psychiatric presentations.
Strengths & limitations
- Brief administration (2–3 minutes) suitable for busy clinical settings
- Strong validity with sensitivity and specificity >80% for major depression
- Excellent test-retest reliability (r > 0.85) and internal consistency (Cronbach's alpha > 0.85)
- Directly parallels DSM-5 diagnostic criteria enabling conceptual clarity
- Item 9 (suicidality) provides immediate flagging for suicide risk requiring clinical action
- Self-report format vulnerable to response bias, insight limitations, and social desirability
- Somatic items (sleep, appetite, fatigue) may reflect medical conditions unrelated to depression
- Not a diagnostic instrument; screen-positive scores require clinical confirmation
- Elevated scores do not distinguish depression from other conditions with overlapping symptoms (anxiety, trauma, medical illness)
- Item 9 (suicidality) provides minimal assessment of actual suicide risk; requires clinical follow-up
Frequently asked
What PHQ-9 score indicates depression?
Typical interpretation: 0–4 (none), 5–9 (mild), 10–14 (moderate), 15–19 (moderately severe), 20–27 (severe). Scores 10 and above are often used as a screening threshold for major depression.
How does the PHQ-9 differ from the BDI?
The PHQ-9 is briefer (9 items vs. 21), aligned with DSM-5 criteria, and intended for screening and monitoring. The BDI is longer, captures more symptom detail, and is more commonly used for severity assessment in clinical samples.
Is the PHQ-9 appropriate for use in primary care?
Yes. The PHQ-9 was specifically designed for primary care settings and is recommended by major guidelines (USPSTF, NICE) for depression screening in non-psychiatric populations.
What should I do if a patient scores high on item 9 (suicidal thoughts)?
Item 9 is a necessary but insufficient indicator of suicide risk. Respond with a careful risk assessment: frequency, intent, plan, means, protective factors, and immediate safety.
Sources
- Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606–613. DOI: 10.1046/j.1525-1497.2001.016009606.x ↗
- Kroenke, K., Strine, T. W., Spitzer, R. L., Williams, J. B. W., Berry, J. T., & Mokdad, A. H. (2009). The PHQ-8 as a measure of current depression in the general population. Journal of Affective Disorders, 114(1–3), 163–173. DOI: 10.1016/j.jad.2008.06.026 ↗
How to cite this page
ScholarGate. (2026, June 3). Patient Health Questionnaire-9. ScholarGate. https://scholargate.app/en/clinical-psychology/phq-9-screening
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
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