The PHQ-9 measures depression symptoms and guides care through its scoring.

What is primarily assessed by the Patient Health Questionnaire-9 (PHQ-9)?

• A. Anxiety levels
• B. Substance use severity
• C. Depression symptoms
• D. Cognitive functioning

Answer: (C)

The Patient Health Questionnaire-9 (PHQ-9) is specifically designed to assess the presence and severity of depression symptoms. It comprises nine questions that reflect the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for major depressive disorder. Each item corresponds to a symptom of depression, such as mood, interest in activities, sleep patterns, energy levels, self-esteem, concentration, appetite, feelings of guilt or worthlessness, and thoughts of self-harm. The responses are tailored to help gauge not only the existence of depressive symptoms but also their impact on daily functioning over the previous two weeks. The scoring system quantifies the severity of these symptoms, which assists healthcare providers in diagnosing depression and monitoring treatment progress effectively. While anxiety levels, substance use severity, and cognitive functioning are important areas of mental health assessment, they are not directly measured by the PHQ-9, making depression symptoms the primary focus of this tool. This specificity is what makes the PHQ-9 a valuable resource in both clinical settings and research regarding mental health.

What the PHQ-9 is really measuring—and why it matters

If you’ve spent time in a care setting, you’ve probably heard about the PHQ-9, short for the Patient Health Questionnaire-9. It’s a small, focused tool, but it carries a lot of weight. Think of it as a quick thermometer for depression symptoms. It isn’t meant to gauge anxiety, substance use, or cognitive functioning directly. Its job is to answer a simple, important question: how strong are depressive symptoms right now, and how much are they affecting everyday life?

Let me unpack what that means in plain terms. The PHQ-9 is tied to DSM-5 criteria for major depressive disorder. In other words, the questions mirror the symptoms a clinician would look for in a diagnostic interview. But instead of a long, drawn-out chat, you get a concise, structured check-in. That efficiency matters—especially in busy clinics, telehealth sessions, or research settings where you want to track change over time without pushing patients to relive every moment of distress.

The nine clues to depression, at a glance

To build a clear picture, the PHQ-9 focuses on nine symptoms. Each item maps to a facet of how mood and daily function can dip when depression is present. Here are the items, in a nutshell:

• Depressed mood most of the day

• Loss of interest or pleasure in almost all activities

• Sleep problems (too much or too little)

• Fatigue or loss of energy

• Changes in appetite or weight

• Feelings of worthlessness or excessive guilt

• Trouble concentrating or making decisions

• Moving or speaking slowly (psychomotor changes) or being fidgety

• Thoughts of death or self-harm

That list isn’t random. It aligns with the core features clinicians look for when they’re assessing depressive disorders. And because each item asks about a symptom over the past two weeks, you get a snapshot that’s recent enough to be actionable but broad enough to spot persistent patterns.

How the scoring paints the picture

Each item on the PHQ-9 is scored from 0 to 3:

• 0 = not at all

• 1 = several days

• 2 = more than half the days

• 3 = nearly every day

Add those nine numbers up, and you get a total between 0 and 27. That total isn’t just a number; it’s a way to gauge severity and monitor change over time. In many settings, the rough guide looks like this:

• 0–4: minimal or no depressive symptoms

• 5–9: mild

• 10–14: moderate

• 15–19: moderately severe

• 20–27: severe

These thresholds aren’t sacred gospel, but they give clinicians a shared language to discuss how hard symptoms are hitting someone’s life. A rise or drop in score over weeks can signal that a treatment tweak might help—or that something else is at play, like life stressors or a medical issue.

Two big caveats whenever you’re reading PHQ-9 scores

Here’s the thing: the PHQ-9 is a potent screener for depression symptoms, but it’s not a stand-alone diagnostic tool. A clinician uses the score as a guide, then follows up with a thorough interview, medical history, and sometimes other assessments to decide whether depression is present and how it should be treated.

Two other important reminders:

• The PHQ-9 doesn’t measure anxiety directly. There are separate tools for that, like the GAD-7. If a patient shows high anxiety alongside depressive symptoms, a clinician will usually assess both and tailor care accordingly.

• It also doesn’t capture all mental health concerns. Cognitive functioning, substance use, and certain personality or mood-related issues require different questions and tools.

In practice, the PHQ-9 shines when you need a rapid, repeatable measure to track how someone is doing across visits. It’s common in primary care, specialty clinics, and research studies because it’s quick, easy to score, and interpretable even when you don’t know the patient’s full history.

A practical glance at real-life use

Let me explain with a quick scene. A patient sits down for a telehealth check-in after starting a new treatment. The clinician administers the PHQ-9, and the score lands in the moderate range. That number doesn’t decide fate, but it nudges the conversation toward what’s working and what isn’t. Are sleep patterns shifting? Is energy returning? Is there renewed interest in activities? Should the clinician consider a tweak in therapy, a change in medication, or additional supports like exercise or sleep hygiene coaching?

What about response over time? If the score drops from, say, 14 to 7 over a few weeks, that’s a sign the current approach is helping. If it stays stubbornly high, the clinician might re-evaluate, rule out other conditions, or broaden the treatment plan. This capacity to monitor progress is what makes the PHQ-9 a staple in modern mental health care.

A quick note on limitations and nuances

Health isn’t a straight line, and neither is mood. A PHQ-9 score can be influenced by temporary life events, cultural factors, or even the way someone interprets a question on a particular day. Language barriers, literacy levels, and the patient’s comfort with disclosure can tilt results. That’s why skilled clinicians pair the PHQ-9 with open-ended questions and, when needed, collateral information from family, friends, or collaborators in care.

If you’re studying these ideas, keep in mind the balance between standardization and personalized care. The PHQ-9 brings consistency—great for comparing patients or tracking trends across a clinic. Yet it does not replace a compassionate, patient-centered conversation that explores a person’s unique story, goals, and context.

A simple study-friendly cheat sheet for students

If you’re tackling material that covers the PHQ-9, here are a few practical anchors to remember:

• The PHQ-9 targets depression symptoms, not anxiety, substance use, or cognitive function.

• It mirrors DSM-5 criteria for major depressive disorder, via nine symptom areas.

• Scoring uses 0–3 per item, with a total score from 0 to 27.

• Two-week time frame is essential: the clock starts at the moment of answering.

• Severity bands help interpret the score, but always pair with clinical judgment.

• It’s a screener and a progress monitor, not a sole diagnostic tool.

• Re-administering over time helps reveal response to treatment (better or worse).

• Be mindful of language, literacy, and cultural factors when administering.

• Compare with related tools (like the GAD-7) when a broader picture of mood and anxiety is needed.

A few analogies to keep the idea clear

Think of the PHQ-9 like a weather report for mood. It’s not a forecast for every day, and it doesn’t tell you the exact cause of a storm. But it’s incredibly useful to know how stormy things are right now and whether the weather is clearing up with treatment, lifestyle changes, or more support. Or picture it as a snapshot of energy and interest—two things that often set the tone for the days ahead. When those are low, it’s natural to ask, “What’s getting in the way, and what would help me feel more like myself again?”

Why this tool matters for learners and clinicians alike

If you’re exploring mental health topics, the PHQ-9 is a great starting point to understand how depression presents across people. It’s simple enough to grasp quickly, yet robust enough to be meaningful in real-world care. The key is not to memorize a number in isolation. It’s to see a number as a guidepost—one part of a bigger conversation about mood, function, and healing.

A closing thought

Depression wears a thousand faces, and the PHQ-9 respects that variety while giving clinicians a clear, structured way to listen for symptoms. It invites patients to articulate how they’re feeling in their own words, and it gives care teams a reliable way to notice change and adjust care with intention. So, when you next encounter the PHQ-9 in your studies or your work, remember: it’s not a verdict; it’s a practical tool that helps bring understanding—and, importantly, a path forward—for people navigating depressive symptoms.

If you’re curious about how these ideas connect with broader mental health assessments, you’ll find that many tools share a similar goal: to illuminate real experiences, guide compassionate care, and keep the focus where it belongs—on the person in front of you. The PHQ-9 is one reliable thread in that larger tapestry, and understanding its scope can make a meaningful difference in both learning and practice.