Over the last two weeks, how often have you been bothered by any of the following problems?
Not at all0
Several days1
More than half the days2
Nearly every day3
Score
01Little interest or pleasure in doing things.
-
02Feeling down, depressed, or hopeless.
-
03Trouble falling or staying asleep, or sleeping too much.
-
04Feeling tired or having little energy.
-
05Poor appetite or overeating.
-
06Feeling bad about yourself - or that you are a failure or have let yourself or your family down.
-
07Trouble concentrating on things, such as reading the newspaper or watching television.
-
08Moving or speaking so slowly that other people could have noticed - or the opposite, being so fidgety or restless that you have been moving around a lot more than usual.
-
09Thoughts that you would be better off dead, or of hurting yourself in some way.
-
0-3score item↑↓moveScored locally - nothing leaves this page
0 of 9
0 / 27
PHQ-90 / 9
Over the last two weeks, how often have you been bothered by any of the following problems?
Scored locally - nothing leaves this page
01Little interest or pleasure in doing things.
02Feeling down, depressed, or hopeless.
03Trouble falling or staying asleep, or sleeping too much.
04Feeling tired or having little energy.
05Poor appetite or overeating.
06Feeling bad about yourself - or that you are a failure or have let yourself or your family down.
07Trouble concentrating on things, such as reading the newspaper or watching television.
08Moving or speaking so slowly that other people could have noticed - or the opposite, being so fidgety or restless that you have been moving around a lot more than usual.
09Thoughts that you would be better off dead, or of hurting yourself in some way.
0 of 90 / 27
02 - The clinician's brief
01 - What it measures
What this scale measures.
The PHQ-9 measures the severity of depressive symptoms over the past two weeks. Its nine items map directly onto the DSM criteria for major depressive disorder: anhedonia, low mood, sleep disturbance, fatigue, appetite change, low self-worth, poor concentration, psychomotor change, and thoughts of death or self-harm. Each item is rated 0-3 by frequency, summing to 0-27.
It reads as a single depression-severity dimension, is sensitive to change, and works both as a screener and as a repeated outcome measure. It does not distinguish unipolar from bipolar depression, and somatic items (sleep, energy, appetite) can be inflated by physical illness.
02 - Origin & purpose
Where it comes from.
Kroenke, Spitzer and Williams published the PHQ-9 in 2001 as the depression module of the Patient Health Questionnaire, derived from the PRIME-MD. It was validated across 6,000 patients in primary care and obstetrics-gynaecology clinics, where a score of 10 or above showed 88% sensitivity and 88% specificity for major depression against an independent mental-health-professional interview.
A 2019 individual-participant meta-analysis across 17,357 patients (Levis et al., BMJ) confirmed sensitivity of about 0.88 and specificity of about 0.85 at the >=10 cutoff. The scale is free to use without permission.
03 - Scoring & cutoffs
How scoring works.
Each item is rated 0 (not at all) to 3 (nearly every day); the total is the simple sum, 0-27, with bands 0-4 minimal, 5-9 mild, 10-14 moderate, 15-19 moderately severe, 20-27 severe. The >=10 cutoff is standard for probable major depression.
A tenth, unscored item asks how difficult the problems have made daily functioning. Any endorsement of item 9 (thoughts of death or self-harm) warrants a direct risk assessment regardless of the total score.
Score
Severity
Interpretation
0–4
Minimal or none
Minimal or no depressive symptoms. Monitor and reassure; no specific treatment usually indicated.
5–9
Mild
Mild depressive symptoms. Watchful waiting; consider repeating the PHQ-9 in two to four weeks.
10–14
Moderate
Moderate depression. A treatment plan should be considered, such as counselling, follow-up or pharmacotherapy.
15–19
Moderately severe
Moderately severe depression. Active treatment with pharmacotherapy and/or psychotherapy is usually warranted.
20–27
Severe
Severe depression. Initiate active treatment and consider referral to a specialist; review risk closely.
04 - Validation evidence
How well it performs.
The original validation reported 88% sensitivity and 88% specificity at >=10; the 2019 BMJ meta-analysis of 17,357 participants found 0.88 sensitivity and 0.85 specificity at the same cutoff. Internal consistency is high (alpha = .86-.89) and 48-hour test-retest reliability is .84. The measure is responsive to treatment change, and a change of 5 or more points is commonly treated as clinically meaningful.
alpha 0.86-0.89
Internal consistency
0.84
Test-retest (48h)
88%
Sensitivity (>=10)
85-88%
Specificity (>=10)
05 - How it compares
How it compares to the alternatives.
Instrument
Items
Time
When to reach for it
PHQ-9
9
~2 min
Default depression screen and repeated outcome measure in most settings. Free.
Clinician-rated, highly sensitive to change - preferred in treatment trials and specialist follow-up.
HAM-D
17
~20 min
Classic clinician-rated severity scale, standard in older antidepressant research.
BDI-II
21
~7 min
Self-report with stronger cognitive coverage; licensed (not free).
HADS
14
~4 min
Screens depression and anxiety while minimising somatic items - useful in medically ill patients.
06 - When to use it
Right tool, wrong tool.
Reach for it when
-Routine screening at intake in primary care or psychiatry
-Tracking treatment response every 2-4 weeks
-Stepped-care thresholds
-Measurement-based care programmes
Reach for something else when
-The patient is medically ill and somatic items dominate (consider HADS)
-You need clinician-rated severity for a trial (MADRS/HAM-D)
-Screening adolescents under 12 (use the PHQ-A for 12-17, other tools below 12)
-Differentiating bipolar depression - the PHQ-9 cannot; add a mania screen such as the ASRM when bipolarity is possible
07 - Confidence & precision
Reading the score with care.
Read a single score as an interval, not a point: short-term fluctuations of 2-3 points are within measurement noise, and a change of 5 or more points is the conventional threshold for clinically meaningful change. Scores near band boundaries (9-11, 14-16) deserve a second administration before treatment decisions rest on them.
08 - Limitations
What it cannot tell you.
The PHQ-9 is a screening and severity tool, not a diagnostic instrument; a positive screen requires a clinical interview against DSM-5 or ICD-11 criteria. It cannot distinguish unipolar from bipolar depression or detect psychotic features. Somatic items are confounded by physical illness, pregnancy and medication side-effects. Item 9 is a prompt for risk assessment, not a suicide-risk measure in itself.
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