Depression is a common mental illness that is both mentally and physically draining. Sometimes the signs and symptoms of depression may be obvious. However, sometimes it can be quite difficult to pick up on, especially in ourselves. Fortunately, there is a quick and simple questionnaire to help assess symptoms of depression. You may have heard of it or may have even taken it before; it’s called the PHQ-9.
What Is a PHQ-9 Form?
The PHQ-9 form is a brief, self-administered questionnaire that assesses depression symptoms. This shorter test is derived from the original and longer PHQ assessment that addresses multiple mental health concerns including depression, panic disorder, anxiety, sleep disorders, and others.
The PHQ was derived from an assessment tool utilized by medical professionals called the PRIME-MD that addresses multiple mental health diagnoses. The PHQ-9 was developed and copyrighted by Drs. R.L. Spitzer, J.B.W. Williams, and K. Kroenke in 1999 with an educational grant from Pfizer, Inc. Pfizer holds the copyright to the PHQ-9, but is available for use and replication without needing permission to be granted.
Since this assessment only addresses depression, the number 9 in the title is a reference to the nine questions to assess each criterion of depression according to the Diagnostic and Statistical Manual of Mental Disorders (or DSM). A self-administered test means that you can answer the questions and tally your result on your own, or by a health or mental healthcare professional. The PHQ-9 is commonly administered in doctor’s or therapist’s offices as a part of routine checkups, or as a way to monitor and evaluate your mental health.
What Does PHQ-9 Stand For?
PHQ-9 stands for Patient Health Questionnaire.
Your PHQ-9 score determines the severity of the depression according to the diagnostic criteria from the Diagnostic and Statistical Manual of Mental Disorders. Once again, there are 9 questions in this assessment; 8 questions directly assessing symptoms of depression and 1 question that assesses how any depressive symptoms have been impacting your ability to function. For each question, there are 4 choices to choose from in regard to how often you have been experiencing symptoms:
- “Not At All”
- “Several Days”
- “More Than Half of the Days”
- “Nearly Every Day”
Selecting “Not At All” will give you 0 points, “Several Days” is 1 point, “More Than Half of the Days” is 2 points, and “Nearly Every Day” is 3 points. Adding up each score will then give you your total score.
PHQ-9 Score Interpretation
Once you’ve taken the PHQ-9 questionnaire, your score will then be interpreted by a mental health professional to find out how severe your depression may be. A PHQ-9 score total of 0-4 points equals “normal” or minimal depression. Scoring between 5-9 points indicates mild depression, 10-14 points indicates moderate depression, 15-19 points indicates moderately severe depression, and 20 or more points indicates severe depression. The higher your score, the more symptoms of depression you experience, and the more severe your depression is.
According to the DSM, Major Depressive Disorder is diagnosed if 5 of 9 symptoms or more, have been present for “more than half the days” of the last 2 weeks, and one of those symptoms being depressed mood or anhedonia. If this criteria is not met, other unspecified depression can still be diagnosed if 2 to 4 symptoms have been present for “more than half the days” in the last 2 weeks, and one of those symptoms being depressed mood or anhedonia. Since each question in the PHQ-9 translates to a criterion of Major Depressive Disorder, it can be a good guide as to what level of depression you would be diagnosed with. Also, it is important to note that if your depression does not meet severe criteria, it does not make your symptoms any less valid.
One of the last questions in the PHQ-9, and a criteria for Major Depressive Disorder, (“thoughts that you would be better off dead or of hurting yourself in some way”) counts if given any score other than a zero, regardless of the duration of the symptom. The final question, found at the end of the symptom assessment portion of the PHQ-9, asks about the test taker’s functionality: “How difficult have these problems made it for you to do your work, take care of things at home, or get along with other people?” In order to accurately diagnose and treat depression, taking into consideration how symptoms impact you, not merely symptoms alone, give a better understanding of the severity.
PHQ-9 Validity and Reliability
The PHQ-9 test is widely used because of its high validity and reliability. Validity studies showed that those who scored a 10 or higher on the PHQ-9 were between 7% and 13.6% more likely to be diagnosed with depression by a mental health professional. Since it is also incredibly easy to administer, it can be given in many health and mental health care settings. This accessibility helps to give us quick and accurate information about the symptoms and severity of someone’s depression. It continues to be an accessible and reliable way to assess depression as it is free to use and is interpreted in over 30 languages. The PHQ-9 can be found in print form, such as this example of a PHQ-9, as well as digital versions, such as found on this website.
Your scores can be used as a way for you to individually monitor where your depression is at, or as a part of your treatment plan with a mental health professional. Since the test is so simple and quick to use, monitoring the severity of your symptoms has never been easier. The PHQ-9 is a fantastic tool to help assess and interpret the symptoms and severity of our depression, but these numbers alone will not provide treatment. It is still necessary to treat depression via therapy, medication, brain-stimulation therapies, self-reflection, or whatever treatment modality is right for you. Insight into our depression is vital, but that alone will not improve the depression. Knowledge is power, and the PHQ-9 helps you and your team to start that process of healing from depression.
American Psychological Association. (2020, June). Patient Health Questionnaire (PHQ-9 & PHQ-2). Retrieved February 2, 2021, from https://www.apa.org/pi/about/publications/caregivers/practice-settings/assessment/tools/patient-health
Kroenke, K., Spitzer, R. L., & Williams, J. B. (2001). The PHQ-9: validity of a brief depression severity measure. Journal of general internal medicine, 16(9), 606–613. https://doi.org/10.1046/j.1525-1497.2001.016009606.x
Pfizer. (n.d.). phqscreeners. Retrieved February 2, 2021, from https://www.phqscreeners.com/
PHQ-9 Depression Test Questionnaire. (n.d.). Retrieved February 2, 2021, from https://patient.info/doctor/patient-health-questionnaire-phq-9
Psychiatric Times. (n.d.). Patient Health questionnaire, including PHQ, PHQ-9, PHQ-Brief, and PHQ-SADS. Retrieved February 2, 2021, from https://www.psychiatrictimes.com/view/patient-health-questionnaire-including-phq-phq-9-phq-brief-and-phq-sads
Stanford Medical. (n.d.). Patient Health Questionnaire (PHQ-9). Retrieved February 2, 2021, from https://med.stanford.edu/fastlab/research/imapp/msrs/_jcr_content/main/accordion/accordion_content3/download_256324296/file.res/PHQ9%20id%20date%2008.03.pdf