PHQ-9 Depression Scale
Patient Health Questionnaire-9 for screening and monitoring depression severity.
How to use & interpret
The PHQ-9 is a nine-item self-report questionnaire for screening and measuring the severity of depression, scored 0–27. Severity bands are commonly: 1–4 minimal, 5–9 mild, 10–14 moderate, 15–19 moderately severe, and 20–27 severe.
Item 9 asks about thoughts of self-harm or being better off dead — a positive response should always prompt a direct risk assessment, regardless of the total score. The PHQ-9 supports diagnosis and tracks response to treatment over time; it does not replace clinical assessment.
Score interpretation
Score 0–4
→ Monitor; may not require treatment
Score 5–9
→ Watchful waiting; repeat PHQ-9 at follow-up
Score 10–14
→ Treatment plan, counselling, follow-up
Score 15–19
→ Active treatment with medication and/or psychotherapy
Score 20–27
→ Immediate initiation of pharmacotherapy; refer to specialist
Interpretation bands for the PHQ-9. Apply clinical judgement and local guidance.
Frequently asked questions
What do I do if item 9 is positive?
Carry out a direct suicide/self-harm risk assessment and act on it, even if the overall score is low. Item 9 is a safety flag, not just a scoring item.
References
- Kroenke K, Spitzer RL, Williams JB. The PHQ-9. J Gen Intern Med. 2001;16(9):606-613.
Related
Curated clinical cross-links plus same-class fallbacks.
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- Lamotrigine (Psychiatric Use) · Mood Stabiliser (Sodium Channel Blocker) — Bipolar Depression
- Acute Behavioural Disturbance / Rapid Tranquillisation · RCEM 2022; RCPsych 2022; NICE NG10
- Self-Harm Presentation · NICE NG225 (2022)
- Capacity Assessment (Mental Capacity Act) · MCA 2005; Code of Practice
- Acute Psychosis Management · NICE CG178 2014
- Depression Management · NICE CG90 2022
- Lithium Therapy Monitoring · NICE CG185
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.