PHQ-9: Patient Health Questionnaire-9
The PHQ-9 is a validated 9-item self-report questionnaire that screens for and measures the severity of depression, widely used in primary care, MIPS quality reporting, and population health monitoring.
What is the PHQ-9?
The Patient Health Questionnaire-9 (PHQ-9) is a self-administered instrument derived from the full PHQ developed by Spitzer, Kroenke, and Williams (1999). It assesses each of the nine DSM-5 criteria for major depressive disorder, asking patients how often they have been bothered by each symptom over the past two weeks. Each item is scored 0 (not at all), 1 (several days), 2 (more than half the days), or 3 (nearly every day), producing a total score of 0–27.
PHQ-9 Score Interpretation
- 0–4: Minimal depression — watchful waiting; repeat PHQ-9 at follow-up
- 5–9: Mild depression — consider counselling, follow-up, and repeat PHQ-9 in 4–6 weeks
- 10–14: Moderate depression — treatment plan, counselling and/or pharmacotherapy
- 15–19: Moderately severe depression — active treatment with pharmacotherapy and/or psychotherapy
- 20–27: Severe depression — immediate pharmacotherapy, referral to specialist, and safety assessment
PHQ-9 in MIPS Quality Reporting
MIPS quality measure 134 (Preventive Care and Screening: Screening for Depression and Follow-Up Plan) requires that adult patients 18 years and older be screened for depression using a standardised tool (PHQ-9 is the most commonly used) and receive a follow-up plan when the screen is positive. The numerator credits the screening plus documentation of a follow-up plan when the screening result is positive. Measure 370 tracks the percentage of patients with a new diagnosis of depression who have a PHQ-9 score follow-up within 6 months.
PHQ-9 Trend Tracking
Serial PHQ-9 administration is the recommended method for monitoring treatment response. A reduction of 5 or more points from baseline is generally considered a clinically meaningful response. Full remission is typically defined as a PHQ-9 score of <5. Analytics that track PHQ-9 trends at the patient and population level — identifying patients who have not had a repeat PHQ-9 within the recommended interval or who have worsening scores despite active treatment — are essential for systematic depression management.