PHQ-9
Also written as: PHQ-9 — Patient Health Questionnaire-9
Patient Health Questionnaire-9, a standardized screening tool used to assess depression severity in clinical settings.
Full Definition
The PHQ-9 (Patient Health Questionnaire-9) is a widely-used, validated self-report instrument designed to screen for depression and monitor treatment response. This nine-item questionnaire corresponds directly to the nine diagnostic criteria for major depressive disorder outlined in the DSM-5, with each item scored from 0 (not at all) to 3 (nearly every day) based on symptom frequency over the past two weeks. Scores range from 0-27, with established cut-off points for mild (5-9), moderate (10-14), moderately severe (15-19), and severe (20-27) depression. The PHQ-9 is valued for its brevity, reliability, and ability to track symptom changes over time, making it an essential tool in psychiatric clinics for both screening and outcome measurement.
Usage
Usage note: Include hyphen in abbreviation; public domain tool requiring no licensing fees.
In Context
- "The patient's PHQ-9 score decreased from 18 to 8 after six weeks of antidepressant treatment." — Progress monitoring note
- "All new patients complete the PHQ-9 at intake as part of routine depression screening protocol." — Clinical procedure manual