Assessment Guide  |   May 9, 2023  |   5 minute read

PHQ-9 | Depression

Patient Health Questionnaire 9 (PHQ-9)

Recommended frequency: Every 2 weeks

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The Patient Health Questionnaire 9 (“PHQ-9”) is a multi-purpose measure used to identify and monitor depression severity. It is a brief, 9-item version of the original PHQ assessment, which measures a variety of mental health challenges in addition to depression, such as anxiety, panic disorder, sleep disorders, and more. The PHQ-9 was co-created by Drs. Robert L. Spitzer, Janet W.B. Williams and Kurt Kroenke in 1999.

About the PHQ-9

The PHQ-9 combines depression diagnostic criteria from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) with other leading major depressive symptoms. The key diagnostic symptom criteria adapted from the DSM-IV includes:

  • Two typical signs of depression: anhedonia (referring to the inability or reduced ability to experience pleasure) and depressed mood;
  • Cognitions (e.g. guilt/worthlessness and suicidality/thoughts of death); and
  • Physical symptoms (e.g. change in appetite, difficulty sleeping and concentrating, feeling tired/slowed down or restless).


Each of the 9 questions rate the frequency of the symptoms, which factors into the severity index.

Clinicians and clinical leaders will often ask about the differences between the PHQ-9 and other depression scales. In comparison to the other commonly used depression scales (BDI, HAD-D, QIDS), the confidence intervals are quite similar, meaning they have all demonstrated reliability, validity, and are responsive to change. The PHQ-9 has a particularly high validity score, such that when PHQ-9 scores were above 10, the measure was shown to have a sensitivity of 88% and a specificity of 88% for Major Depressive Disorder—meaning that a score above 10 was a good indication that a diagnosis of depression would occur. Each of the major depression scales have their differences, although the PHQ-9 and BDI-II in particular tend to measure relatively equal levels of severity and track symptom change in a similar manner. The PHQ-9 is often preferred to other comparable assessments due to its brevity, which makes it easy to integrate into research or practice, and helps promote high completion rates.

Who is the PHQ-9 Assessment for?

Review the list below to determine if this assessment should be used with your client. If you answer NO to all four questions, the PHQ-9 is a good fit to use with your client.

  1. Is your client experiencing normal bereavement?
  2. Does your client have a history of Manic Episodes (Bipolar Disorder)?
  3. Does your client have a physical disorder or are they taking medication, or other drugs that may be the biological cause of the depressive symptoms?
  4. Is your client under 18? If they are, please refer to the Child Depression & Anxiety (RCADS 25) measure or the Child Depression (CES-DC) measure.

Note: The PHQ-9 can also be used for patients with stroke, and is suitable for geriatric patients, patients with traumatic brain injury, in primary care and obstetrics-gynaecology settings, and with members of the general population.

The Scale

The scale is made up of 9 items that target symptoms of major depressive disorder. Since this assessment relies on clients to self-report, it’s important that you verify the answers with them in session to ensure they understood each question, and to gather any other relevant information and context they provide about their symptoms and experience.

The PHQ-9 requires the client to provide answers based on how often they experienced the below challenges, over the course of the last 2 weeks.

Copy of the PHQ-9 Assessment to be used to identify and monitor depression

Scoring the PHQ-9

A diagnosis of Major Depressive Disorder should be considered if there are 5 or more items that score in the shaded section, with one of these items being #1 or #2.

Other depressive disorders should be considered if the client presents 2-4 items in the shaded section, with one corresponding to #1 or #2.

You can then determine the severity by adding up the overall score:

Depression severity is calculated by assigning scores of 0, 1, 2, and 3, to the response categories of “not at all”, “several days”, “more than half the days”, and “nearly every day”, respectively. The PHQ-9 total score for the nine items ranges from 0 to 27. The table below outlines the score groupings and proposed treatment actions. Scores of 5, 10, 15, and 20 represent respective cutpoints for mild, moderate, moderately severe and severe depression. The PHQ-9 is also sensitive to change, meaning depression severity and symptom frequency that increases or decreases during treatment can be recorded through regular, repeat assessments.

Ultimately, the higher a client scores, the more severe their depression is.

Note: Question 9 is a single screening question to identify suicide risk. Any client who answers ‘yes’ to question 9 needs further assessment to determine their risk level and inform the appropriate next steps. When this assessment is completed on the Greenspace platorm, a [insert flag from GS system] and date of response are placed the client profile to highlight suicidality, which indicates that the client has scored 1 or above on this PHQ-9 item or another measure that monitors for this risk.

Screenshot 2023 05 08 at 4.33.15 PM

TIP: When discussing scores with clients, it’s important to remind them that even if they do not meet severe criteria, it does not mean their symptoms are any less valid. This is a good opportunity to dig in to each symptom they report, in order to identify other potential root causes, work on coping mechanisms, and to inform treatment goals and approach moving forward.

Practice: PHQ-9 Three Ways

The ‘PHQ-9 Three-Ways’ exercise is used by our partners at the Yale Measurement-Based Care Collaborative to help clinicians feel comfortable exploring assessment results with clients and getting curious about what the scores mean. This process is key to driving collaborative discussions with clients and helping to inform treatment decisions.

During our second panel with the Yale MBCC attendees participated in this practice exercise. The Yale MBCC team shared example PHQ-9 scores from three different clients, each with slightly different responses. Attendees then reviewed the responses and shared what they noticed, what hypotheses they were forming, and what they might ask the client in session to dig deeper into their experience.

Watch this clip for guidance on how to practice interpreting PHQ-9 results for yourself or your clinical team:

Learn more about this exercise and some of the key takeaways from the session here.


Copyright Information
Developed by Drs. Robert L. Spitzer, Janet B. W. Williams, Kurt Kroenke and colleagues. No permission required to reproduce, translate, display or distribute.

American Psychological Association. (2020, June). Patient Health Questionnaire (PHQ-9 & PHQ-2).
Kroenke, K., Spitzer, R. L., & Williams, J. B. (2001). The PHQ-9: validity of a brief depression severity measure. Journal of general internal medicine16(9), 606–613.

The information provided above was derived from materials and research developed by the creators and/or licensors of the BR-WAI. The information may not be exhaustive and is not a treatment recommendation by Greenspace.

Frequently Asked Questions
Can the PHQ-9 be used for diagnosis?

The PHQ-9 is widely used for diagnosing depression and determining the severity of depression a client is experiencing. It’s important to always discuss each item with the client and ensure they understood the questions, and to gather additional insight into their symptoms and experiences, prior to making a diagnosis.

How often should the PHQ-9 be administered?

To best monitor and respond to symptom changes, the recommended frequency for the PHQ-9 is every 2-4 weeks. A brief and consistent frequency allows the assessment to capture client experiences over the two weeks prior to completion, providing an opportunity to get curious about the results with your client. By digging into the symptoms and uncovering potential causes, you can work together to better understand the factors that may influence their symptom changes.

Can the PHQ-9 be used with all ages?

The PHQ-9 is validated for individuals 18 years of age or older. If you’re looking for measures for younger age groups, please refer to the Child Depression & Anxiety (RCADS 25) measure or the Child Depression (CES-DC) measure.

How long does it take to complete the PHQ-9

The PHQ-9 takes approximately 2-5 minutes to administer and can be completed independently by the client or in session with their clinician.

What’s the difference between the PHQ-9 and other assessments that measure depression?

Compared to other commonly used depression scales (eg. BDI, HAD-D, QIDS), the PHQ-9 presents similar confidence intervals, in terms of demonstrated reliability, validity, and responsiveness to change in symptoms and severity. While all major depression scales are different, the PHQ9 and BDI-II are most similar in their ability to measure relatively equal levels of severity and their approach to monitoring symptom change. The PHQ-9 is most often preferred because of its brevity (9 questions vs. 21 questions), which makes it easier for clients to complete and ultimately allows for a more successful integration into practice, especially when clients are assigned multiple assessments as part of their treatment plan. Though brief, the PHQ-9 has a high validity score, such that when PHQ-9 scores were above 10 (moderate-severe), the measure was shown to have a sensitivity of 88% and a specificity of 88% for Major Depressive Disorder—meaning that a score above 10 was a good indication that a diagnosis of depression was appropriate.

What should I do if my client receives a flag for suicidality (i.e. responds ‘Several Days’ or any higher frequency to question 9)?

Any client who responds with ‘Several Day’ or any higher frequency to question 9 requires further assessment to determine their suicidality risk level and inform the appropriate next steps. Recognizing and appropriately responding to suicidal ideation often requires suicide prevention and response training. If you do not feel equipped to asses the risk level of your client, it is a good idea to refer them to someone who is trained to respond to and treat suicidality. The important thing is to ensure your client is safe and work to maintain their trust while still asking the questions necessary to understand their risk and determine the appropriate treatment response.

When interviewed, Kristin Bruns (LCP, and Assistant Professor in the Department of Counseling, School Psychology and Educational Leadership at Youngstown State University) shared that it’s important to first build a strong bond with your client and generate a deep understanding of their situation, prior to intervening. Clients dealing with these thoughts and feelings often need a clinician who will listen and demonstrate empathy, rather than one who will immediately jump into action. When it comes time to ask more questions, it is recommended to choose evidence-based suicide assessments and treatment tools, and continue to get curious with the client on their responses without overwhelming them.

To learn more about assessing and responding to suicide risk, review this article.

How can I practice using the PHQ-9 with client’s in session?

During our 2nd educational panel with the Yale Measurement-Based Care Collaborative, we all participated in an important exercise to illustrate how simple, yet valuable, using MBC in care can be. The ‘PHQ-9 Three-Ways’ exercise is used by the team at Yale to help any service provider feel comfortable with the simple process of exploring MBC data and getting curious about PHQ-9 responses, collaboratively with their clients, to understand the meaning and impact of their results.

The Yale MBC Collaborative shared sample PHQ-9 scores from three different clients, each with slightly different responses. The audience then reviewed the responses and highlighted what stood out to them, what hypotheses they were forming, and what they might ask the client in session to dig deeper into their experience, understand their perspective and inform treatment discussions and decisions.

Get started by watching this clip and try it for for yourself:

Why did my client score low on the PHQ-9 even though they appear to be experiencing significant amounts of depression?

There are times when what is shown in your clients data, does not align with what they share in care or with how it seems like they’ve been doing overall. This is the perfect time to dive into each of the items on the measure and ensure that you and your client are speaking the same language and understanding them correctly. Their understanding of the language of the measure will impact how they respond, so it’s important that they have a strong understanding of what the question is asking and that you, as their provider, have a strong understanding of how they interpret the language. By getting curious together, you can begin to better understand what the questions and language mean to them, and how that might impact your understanding of their experience.

With a fulsome understanding, there is still often a discrepancy between what what your client is telling you verbally and what their results are showing, highlighting this outlines a large part of the impact of Measurement-Based Care integrated into treatment processes. This presents the perfect opportunity to dig a bit deeper and focus a part of your session around that specific item to learn more about their experience in care and mental health challenges. Doing so will help build your client-clinician bond and ensure that your clients voice and experiences are at the heart of the care process and treatment decisions.

How should I administer the PHQ-9 to clients?

The PHQ-9 can be completed in two ways:

  1. Independently by the client, whether this on their own schedule at home (Greenspace offers automatic delivery for completion on desktop or mobile via text or email) or at the office before session (via tablet, kiosk or pen/paper)
  2. Administered verbally by staff before session or in-session. This can be particularly helpful, and sometimes necessary, when working with clients who have difficulty with reading or comprehension.

Research shows that clients can fill out this assessment successfully on their own and most often require no assistance. However, it’s important to discuss each question before or after completion to ensure you have a shared understanding of what the questions are asking. If you choose to administer the assessment verbally, be sure to ask the question exactly as it is written to ensure their response is accurate and results remain evidence-based.

How do I share the purpose of this form with clients, so they understand why they’re filling it out?

It’s important that clients understand the value of this assessment prior to being asked to complete it. Making the process of measurement valuable to clients is the best way to deepen their engagement in treatment and improve therapeutic alliance and clinical outcomes. For inspiration, here is an example of how you might introduce the PHQ-9 to clients:

“Just like you have your blood pressure taken when you go to the doctors, this assessment is the providers way of measuring your mental well-being. The results we get throughout the course of your treatment will be our way of checking in on your progress, so we can better understand what’s working and what might need to change, talk more deeply about your symptoms and experiences and work together to set goals in treatment, so we both know we’re working towards what matters to you.”

Jessica Barber, PhD, explains this process well and shares how she approaches introducing measures to clients in session: