PHQ-9 Explained: Scoring and Use in Primary Care
The PHQ-9 is a nine-item questionnaire that measures depression symptom severity over the past two weeks. Each item scores 0 to 3, for a total of 0 to 27. Higher scores mean more severe symptoms. Primary care uses it two ways: to screen for depression, and to track whether treatment is working over time.
The PHQ-9 is one of the most widely used depression tools in medicine because it is short, free, and validated. It maps directly to the diagnostic criteria for major depression, so a clinician can move from a number to a clinical conversation quickly. But a score is a starting point, not a diagnosis. Here is how it works and how it fits into care.
The PHQ-9 is the depression module of the Patient Health Questionnaire, a self-report tool patients can complete in a few minutes. It asks how often, over the last two weeks, the patient has been bothered by nine problems — low mood, loss of interest, sleep changes, fatigue, appetite changes, feelings of failure, trouble concentrating, moving slowly or being restless, and thoughts of being better off dead or hurting oneself.
Those nine items line up with the criteria clinicians use to diagnose major depressive disorder. That alignment is what makes the tool useful: it is not a vague mood check, it is a structured measure tied to how depression is actually defined.
A shorter version, the PHQ-2, uses only the first two items (mood and interest) as a quick first pass. A positive PHQ-2 is usually followed by the full PHQ-9.
Each of the nine items is rated on the same 0-to-3 scale based on frequency over the past two weeks:
Add the nine responses for a total score from 0 to 27. The math is simple, which is part of the point — any staff member can score it consistently, and the patient can complete it on paper, a tablet, or a portal before the visit.
A tenth question, asked separately, gauges how difficult these problems have made the patient's daily functioning. It does not count toward the total but adds context about impact.
Total scores fall into severity bands that are widely used as a general guide:
A score of 10 or higher is the cutoff many practices use to flag likely major depression and prompt a closer clinical look. Validation studies put the sensitivity and specificity of that cutoff around the high-80s percent range, which is why it is a common threshold — but it is a signal to evaluate, not a verdict.
Two things matter more than the band label. First, item 9 — thoughts of self-harm or suicide — is reviewed on its own, regardless of the total score, and any positive answer triggers a safety assessment. Second, the number only means something in clinical context. A score reflects self-reported symptoms; a clinician confirms whether they represent depression, another condition, or a temporary reaction to circumstances.
As a screening tool, the PHQ-9 (or the PHQ-2 followed by the PHQ-9) helps a practice catch depression it might otherwise miss. Many people with depression present to primary care for physical complaints — fatigue, pain, sleep problems — and never raise mood directly. A routine questionnaire surfaces symptoms without requiring the patient to bring them up first.
Screening only helps if a positive result leads somewhere. A number on a form does nothing on its own; the value comes when an elevated score connects to assessment, diagnosis, and a treatment plan. That is why screening works best inside a system built to act on the result, not as a standalone form.
Beyond screening, the PHQ-9 is the backbone of measurement-based care — repeating the same measure over time to see whether treatment is actually working. This is sometimes called treat-to-target: pick a goal, measure toward it, and change the plan if the numbers do not move.
The common targets come from the score itself:
Instead of assuming a prescription or referral solved the problem, the care team re-administers the PHQ-9 at regular intervals. If the score is falling, the plan is working. If it has stalled after several weeks, that is a prompt to adjust — change a dose, switch treatment, add therapy, or consult a psychiatrist. The tool turns "how are you feeling?" into a trend a team can act on.
The PHQ-9 is central to the Collaborative Care Model (CoCM), an evidence-based approach with more than 90 randomized controlled trials behind it. In collaborative care, a behavioral health care manager tracks each patient's PHQ-9 over time in a registry, the primary care clinician manages treatment, and a consulting psychiatrist reviews patients whose scores are not improving.
The measure is what makes the model systematic. Because every patient has a running PHQ-9 trend, no one gets lost after an initial visit — the registry flags stalled scores so the team can step in. The questionnaire is the shared language that keeps screening, treatment, and follow-up connected.
The PHQ-9 is a strong tool, but it has boundaries worth naming:
Used well — as a repeated measure inside a system that acts on the result — the PHQ-9 turns a subjective symptom into something a care team can track and treat. Used in isolation, it is just a number on a page.
A total of 0 to 4 is generally considered minimal or no depressive symptoms. Scores of 5 to 9 suggest mild symptoms that may warrant monitoring, and 10 or higher typically prompts a closer clinical evaluation for depression.
A score of 10 or higher is a widely used threshold that flags likely major depression and prompts further assessment. It is a screening signal, not a diagnosis — a clinician confirms whether the symptoms represent depression and what treatment fits.
In measurement-based care, the PHQ-9 is re-administered at regular intervals during treatment — often every few weeks early on — so the team can see whether symptoms are improving and adjust the plan if the score is not falling toward response or remission.
No. The PHQ-9 measures the severity of depressive symptoms and supports diagnosis, but it does not replace clinical judgment. A qualified clinician interprets the score alongside history, examination, and context to reach a diagnosis.
Item 9 asks about thoughts of being better off dead or of hurting oneself. It is reviewed independently of the total score, and any positive response prompts a direct safety assessment, regardless of how mild or severe the overall score appears.
