Patient Health Questionnaire-9 (PHQ-9)

The PHQ-9 (Kroenke 2001) screens for and grades the severity of depressive symptoms over the prior two weeks. Nine DSM-based items are each scored 0–3 (total 0–27), with cut-points for minimal, mild, moderate, moderately severe, and severe depression; a score ≥ 10 has ~88% sensitivity and ~88% specificity for major depression. Item 9 screens for suicidal ideation and warrants urgent evaluation when endorsed.

Mental Health General MedicineEvidence-BasedUpdated 2026-08-16

Little interest or pleasure in doing things*

Feeling down, depressed, or hopeless*

Trouble falling or staying asleep, or sleeping too much*

Feeling tired or having little energy*

Poor appetite or overeating*

Feeling bad about yourself — or that you are a failure or have let yourself or your family down*

Trouble concentrating on things, such as reading the newspaper or watching television*

Moving or speaking so slowly that other people could have noticed; or the opposite — being so fidgety or restless that you have been moving around more than usual*

Thoughts that you would be better off dead, or of hurting yourself in some way*

Any endorsement (1 or higher) warrants an immediate suicide risk assessment.

Clinical Notes

Formula

PHQ-9 total = sum of 9 item scores (each 0–3, over the past 2 weeks) → 0–27. 0–4 minimal, 5–9 mild, 10–14 moderate, 15–19 moderately severe, 20–27 severe.

Normal Range

0–9 (no/minimal to mild symptoms). A total ≥ 10 is the recommended threshold for major depressive disorder and warrants treatment and follow-up.

Clinical Notes

The Patient Health Questionnaire-9 is the 9-item depression module of the PRIME-MD diagnostic instrument. Each item corresponds to one of the nine DSM-5 criteria for major depressive disorder and is scored 0 (not at all) to 3 (nearly every day) for the previous two weeks, giving a total of 0–27. A cut-point of 10 maximizes combined sensitivity (~88%) and specificity (~88%) for major depressive disorder. Severity bands are 0–4 (minimal), 5–9 (mild), 10–14 (moderate), 15–19 (moderately severe), and 20–27 (severe). Item 9 explicitly probes suicidal ideation and, when endorsed, requires urgent evaluation regardless of the total score.

References

Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606-613.
Spitzer RL, Kroenke K, Williams JB. Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. JAMA. 1999;282(18):1737-1744.

Calculator Information

Specialty

General Medicine

📋 Reference Ranges

Normal Range

0–9 (no/minimal to mild symptoms). A total ≥ 10 is the recommended threshold for major depressive disorder and warrants treatment and follow-up.

Reference ranges for this calculator
Classification	Range
None/Minimal Minimal depressive symptoms	0–4
Mild Mild symptoms; consider watchful waiting with follow-up	5–9
Moderate Moderate depression; initiate or adjust treatment	10–14
Moderately severe Moderately severe depression; active treatment	15–19
Severe Severe depression; intensive treatment and urgent review	20–27

What This Calculator Measures

Screens for and grades the severity of depressive symptoms over the previous two weeks and identifies possible suicidal ideation, guiding treatment initiation and follow-up in primary care.

How to Use

Ask the patient to rate each of the nine symptoms for the past two weeks using the four frequency options (0 = not at all to 3 = nearly every day).
Sum the nine item scores to obtain the PHQ-9 total (0–27).
Review the severity band and, whenever item 9 is endorsed, perform an immediate suicide risk assessment.

Interpretation Guide

Total 0–4 = minimal, 5–9 = mild, 10–14 = moderate, 15–19 = moderately severe, and 20–27 = severe depression. A total ≥ 10 has ~88% sensitivity and ~88% specificity for major depressive disorder and is the recommended threshold for initiating treatment. Any endorsement of item 9 requires urgent evaluation regardless of the total.

Clinical Significance

The PHQ-9 is the most widely used brief depression severity measure; its validated cut-point of 10 makes it a practical case-finding and monitoring tool that directly quantifies each DSM-5 depressive criterion and screens for suicidal ideation.

When to Use

Routine depression screening in primary care
Assessment of patients with low mood, anhedonia, fatigue, or sleep disturbance
Monitoring response to depression treatment
Patients with chronic illness associated with depression

When Not to Use

As a standalone diagnostic instrument without clinical assessment
To grade symptoms in patients who cannot comprehend the questionnaire (severe cognitive impairment, language barriers)
In acute emergencies — a positive suicide screen requires immediate action, not delayed scoring

Limitations

Self-report may under- or over-estimate symptom severity.
A score of 10 identifies probable depression; the diagnosis requires clinical confirmation.
Somatic symptoms (fatigue, sleep disturbance) may reflect physical illness rather than depression.

Worked Example

A 46-year-old woman reports two weeks of low mood and loss of interest. She scores 2 (more than half the days) for anhedonia and depressed mood, 3 for sleep disturbance, 2 for fatigue, 1 for appetite change, 0 for guilt, 2 for poor concentration, and 1 for slowed movements; she denies suicidal ideation (item 9 = 0).

Inputs:

phq1: 2

phq2: 2

phq3: 3

phq4: 2

phq5: 1

phq6: 0

phq7: 2

phq8: 1

phq9: 0

PHQ-9 = 2 + 2 + 3 + 2 + 1 + 0 + 2 + 1 + 0 = 13/27 — MODERATE depressive symptoms. A score ≥ 10 supports initiating treatment (e.g., antidepressant and/or psychotherapy) with close follow-up.

Evidence

Source: Psychiatry / Primary Care
Reference: Kroenke K, Spitzer RL, Williams JB. J Gen Intern Med. 2001;16(9):606-613.
Reviewed By: MedCalcHub Clinical Team
Version: 2001
Updated: 2026-08

Kroenke K, Spitzer RL, Williams JB. J Gen Intern Med. 2001;16(9):606-613.

References

Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606-613. (Validation study)
Spitzer RL, Kroenke K, Williams JB. Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. JAMA. 1999;282(18):1737-1744. (Primary care validation)

Frequently Asked Questions

When should I act on item 9?

Any endorsement of item 9 (thoughts of being better off dead or of self-harm), even a score of 1, warrants an immediate, direct suicide risk assessment and urgent management.

How much change on the PHQ-9 is clinically meaningful?

A change of 5 points is the conventional minimal clinically important difference when monitoring treatment response.

Disclaimer: This calculator is intended for educational and clinical decision support purposes only. The PHQ-9 is a screening instrument, not a substitute for a clinical diagnostic assessment; any concern for self-harm requires immediate evaluation.

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Patient Health Questionnaire-9 (PHQ-9)

Clinical Notes

Formula

PHQ-9 total = sum of 9 item scores (each 0–3, over the past 2 weeks) → 0–27. 0–4 minimal, 5–9 mild, 10–14 moderate, 15–19 moderately severe, 20–27 severe.

Normal Range

0–9 (no/minimal to mild symptoms). A total ≥ 10 is the recommended threshold for major depressive disorder and warrants treatment and follow-up.

Clinical Notes

References

Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606-613.
Spitzer RL, Kroenke K, Williams JB. Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. JAMA. 1999;282(18):1737-1744.

Calculator Information

Specialty

General Medicine