Depression self-assessment: PHQ-9 scoring and severity bands

Key Takeaways

Depression self-assessment tools like the PHQ-9 screen for symptoms. They can’t diagnose depression on their own.

The PHQ-9 is the most widely used depression tool in primary care, scoring nine DSM-5 symptoms 0 to 3 for a total of 0 to 27.

Severity bands guide the next step: 5-9 mild, 10-14 moderate, 15-19 moderately severe, 20-27 severe, and any positive answer on item nine needs same-day follow-up.

Pabau’s digital intake forms can embed a validated screening tool at check-in, score it automatically, and flag a high-risk result for staff follow-up.

A patient tells you they’re just tired lately, sleeping badly, and not enjoying much. That could be a rough month, or it could be depression hiding behind vague complaints. A ten-minute conversation rarely settles it either way.

A depression self-assessment gives you a faster, more reliable read. The PHQ-9 turns nine simple questions into a score you can act on within minutes, and it’s the tool most practices reach for first. Get the scoring right, though, and one single answer on that list can matter more than the total ever will.

What counts as a depression self-assessment?

A depression self-assessment is a validated questionnaire that flags patients who may have depression. It doesn’t diagnose anything. The most common version, the PHQ-9 (Patient Health Questionnaire), scores nine symptoms drawn straight from the DSM-5 criteria for major depression.

Those nine symptoms cover mood, interest, sleep, energy, concentration, appetite, guilt, movement, and thoughts of self-harm. Patients rate how often each symptom showed up over the past two weeks. They use a simple scale from 0 to 3: not at all, several days, more than half the days, or nearly every day.

That distinction matters more than it sounds. A self-assessment score is a starting point for a conversation, not an endpoint. The WHO’s depression self-assessment tool, for example, asks about diagnosis history, prior treatment, and current symptoms, then calculates and evaluates a score. Turning that score into a clinical judgment, and deciding what happens next, is still down to a trained health professional.

The US Preventive Services Task Force gives depression screening in primary care a Grade B recommendation. That means it should be offered to every adult patient. The PHQ-9 is the tool most guidelines point to for that job. It takes just two to three minutes and maps directly onto DSM-5 criteria.

The nine symptoms the PHQ-9 actually asks about

Each PHQ-9 item maps to one DSM-5 depression criterion. That lets a clinician see exactly which symptom is driving a high score.

• Depressed mood: persistent sadness or emptiness, most of the day
• Anhedonia: losing interest or pleasure in things you’d normally enjoy
• Sleep disturbance: insomnia, oversleeping, or sleep that doesn’t feel restful
• Fatigue: low energy that doesn’t track with activity level
• Appetite change: eating a lot more or a lot less than usual
• Concentration difficulty: trouble focusing, reading, or making everyday decisions
• Guilt or worthlessness: excessive self-blame or feeling like a burden
• Psychomotor changes: visibly slowed movement and speech, or restlessness
• Suicidal ideation: thoughts of death, self-harm, or suicide

That last item, question nine, deserves its own flag. Any answer above “not at all” needs a same-day safety conversation, no matter what the total score comes out to. We’ll come back to that in the scoring section below.

Appetite change is easy to underestimate on a nine-item form. A whole food diet plan template gives you a simple way to track intake changes alongside the score, rather than letting that answer get lost in the total.

How the PHQ-9 compares against other depression scales

The PHQ-9 isn’t the only validated option. Clinicians pick a tool based on setting, patient population, and how much time they have. The table below lines up the most common ones.

Public domain tools cost nothing and need no license request. The Beck Depression Inventory is the exception. It’s copyrighted by Pearson and requires a paid license, which is why most primary care practices default to the PHQ-9, WHO-5, or Hamilton scale instead.

Scoring the PHQ-9: What the numbers actually mean

Add up the nine item scores for a total between 0 and 27. That number sorts into five severity bands, and each band points to a different next step.

Severity bands and the action each one calls for

A score under 5 needs no action beyond routine care. From 5 to 9, watchful waiting is enough, with a repeat PHQ-9 at the next visit. Once the total reaches 10, it’s time to build a treatment plan that may include counseling, medication, or both. From 15 to 19, that treatment should already be active.

Anything at 20 or above calls for pharmacotherapy right away. If the impairment is severe or the response is poor, add an expedited referral to a mental health specialist.

Item nine overrides the total score. If a patient answers anything other than “not at all” on the suicidal ideation question, ask directly about intent and plan. Confirm access to means before they leave the room. A low total score doesn’t cancel out a positive answer here. Document exactly what you asked and what the patient said, not just the number.

WHO-5 and Zung: Two alternatives worth knowing

The PHQ-9 isn’t always the right fit. Some practices prefer a shorter well-being check, others need a more detailed research-grade tool. Two options come up often.

WHO-5 Well-Being Index

The WHO-5 skips symptom checklists and asks about well-being instead. Patients rate five statements, like feeling cheerful or waking up rested. Each uses a scale from 0 to 5 over the past two weeks. Add the five scores for a raw total of 0 to 25, then multiply by 4 to get a percentage. A result of 50 or below suggests low mood. A result of 28 or below points to probable depression that needs a fuller assessment.

Zung Self-Rating Depression Scale

The Zung scale takes longer. It has 20 items, each rated on a 4-point frequency scale, for a raw total between 20 and 80. It digs deeper than the PHQ-9, which makes it more common in psychiatry and research than in a busy primary care visit. Converted to the standard SDS index, a result of 50 or higher generally signals clinical depression that needs specialist evaluation.

Administering the PHQ-9 without derailing the visit

The PHQ-9 works best as a rhythm, not a one-off. Most practices give it at intake, then repeat it every few weeks during active treatment. They give it again at discharge to prove the treatment actually worked.

Before you hand over the form

• Confirm this is the right tool for the patient’s age; the standard PHQ-9 is validated for adults, not children.
• Explain in one line why you’re asking, so it doesn’t feel like a hidden test: “We ask everyone these nine questions as part of a standard checkup.”
• Have a plan ready for a positive item nine before you hand out the form, not after.

A simple administration workflow

1. Baseline: administer at intake or the first visit where mood is a concern.
2. Ongoing: repeat every 4 to 8 weeks during active treatment.
3. Discharge: score again at treatment end to measure the change.
4. Document: log the raw score, severity band, and your clinical read in the chart, not just a number. A BIRP note format keeps that consistent across visits.
5. Act: match the follow-up to severity. A severe score doesn’t sit in an inbox until next week; a moderate one can usually wait for the next scheduled visit.

A few mistakes show up again and again. Handing over the form without context, so the patient rushes through it or feels judged. Filing the score without recording the severity band, which leaves the next clinician guessing. And treating a positive item nine as routine because the total score wasn’t high, when a single symptom can outweigh the sum.

How Pabau supports depression screening in your practice

Practice management software like Pabau lets you build the PHQ-9, or any validated tool, straight into your digital intake forms.

Patients complete it on a tablet or their phone before the appointment, and the score calculates itself, with the result landing in the patient record automatically, so there’s no spreadsheet or paper file to lose track of. The same setup works whether you’re running general intake or a dedicated mental health EMR.

That single record matters more than it sounds. When screening lives next to treatment notes and prescriptions, nothing gets missed because a form sat in a drawer. Automated workflows can flag a high-risk score for staff follow-up, so it doesn’t wait for someone to notice.

Where depression self-assessment tools fall short

Self-assessment tools screen. They don’t diagnose. A high PHQ-9 or WHO-5 score doesn’t rule out other causes behind the same symptoms. Thyroid disease, anemia, medication side effects, grief, and substance use can all push a score up. A clinical interview still decides what’s actually going on.

• False negatives: shame or poor symptom awareness can make a patient underreport; always ask a couple of follow-up questions regardless of the score
• False positives: grief, thyroid disorders, and some medications can push a score up without depression being the cause
• Cultural fit: tools validated mostly in Western populations may not perform the same way everywhere; adjust your threshold for suspicion accordingly
• Comorbidities: depression often travels with anxiety or substance use, and a depression-specific tool won’t catch either one
• Item nine, again: any positive answer on the suicidal ideation question needs same-day follow-up, whatever the total score says

Treat a self-assessment score as one input, not the whole decision.

Billing depression screening the right way

Depression screening isn’t just good practice. In most settings, it’s billable too, provided the documentation holds up.

Medicare covers one annual depression screening a year under HCPCS code G0444, but the billing rules depend on the visit. It’s bundled into the Initial Preventive Physical Exam (G0402) and the Initial Annual Wellness Visit (G0438).

Both already require depression screening as a core element, so G0444 can’t be billed separately alongside either one. A Subsequent Annual Wellness Visit (G0439) doesn’t require screening as a core component, which makes G0444 separately billable there. It can also stand alone at another covered visit, provided the documentation supports it.

Outside Medicare, most commercial payers use CPT code 96127 instead, for a brief emotional or behavioral assessment with a standardized instrument. It’s billed per instrument, so a PHQ-9 plus a GAD-7 anxiety check can each earn a unit, up to the plan’s daily limit.

There’s no specialty restriction on who can use this code. Any qualified professional can bill it for a tool like the PHQ-9 or GAD-7, from primary care to routine therapy practice management. Payer rules and per-day unit caps still apply.

Once you’ve screened, two quality codes track the outcome for MIPS reporting. G8431 applies when the result is positive and a follow-up plan is documented. G8510 applies when the result is negative and no plan is required. Neither pays directly; they’re quality-measure codes. Picking the wrong one creates a documentation mismatch an auditor will catch.

Make depression screening a habit, not an annual box to tick

A validated depression self-assessment, most often the PHQ-9, turns a vague hunch into a number you can act on. It won’t diagnose anyone. What it will do is flag who needs a closer look and track whether treatment is working. It also gives you a defensible record of what happened when a score demanded action.

If you’re ready to build a screening tool straight into your intake process, rather than chasing paper forms, book a demo. We’ll show you how Pabau handles the scoring and the follow-up automatically.

Continue your research

Screening for anxiety too? GAD-7 anxiety assessment uses the same scoring style and pairs naturally with the PHQ-9 at intake.

Working with a younger patient? Children’s depression inventory is the validated pediatric equivalent of the PHQ-9.

Need the billing side sorted? HCPCS G8431 billing guide walks through documenting a positive depression screen for MIPS reporting.

Standardizing documentation for other conditions? Diabetic ketoacidosis care plan uses the same structured format for a different chronic condition.

Frequently asked questions about depression self-assessment tools