Quick Look

The PHQ-9 is the nine-item depression scale of the patient health questionnaire. It is one of the most validated tools in mental health and can be a powerful tool to assist clinicians with diagnosing depression and monitoring treatment response. The nine items of the PHQ-9 are based directly on the nine diagnostic criteria for major depressive disorder in the DSM-IV.​

It is essential that you have something in place that promotes “treat-to-target” care – that is, keeping track of patient symptoms and problems and systematically tracking whether or not the treatments are helping. Tracking tools, especially the PHQ-9, are one of the easiest ways to do this. The PHQ-9 is somewhat unique in that it functions as a screening tool, an aid in diagnosis, and as a symptom-tracking tool that can help track the overall severity of a patient’s depression as well as the improvement of specific symptoms with treatment.

Advantages of PHQ-9

  • Shorter than other depression rating scales
  • Can be administered in person by a clinician, by telephone, or self-administered
  • Facilitates diagnosis of major depression
  • Provides assessment of symptom severity
  • Is well-validated and documented in a variety of populations
  • Can be used in adolescents as young as 12 years of age
  • Included FREE with the Kipu EMR

The Patient Health Questionnaire for Depression (PHQ-9)

The PHQ-9 is a multipurpose instrument for screening, diagnosing, monitoring, and measuring the severity of depression. It incorporates DSM-IV depression diagnostic criteria with other leading major depressive symptoms into a reliable self-reporting tool.

This easy-to-use patient questionnaire is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders. The PHQ-9 is the depression module, which scores each of the nine DSM-IV criteria as “0” (not at all) to “3” (nearly every day). It has been validated for use in primary care.

It is not primarily a screening tool, although it can be used in that capacity. But it is used to monitor the severity of depression and response to treatment. It can be used to make a tentative diagnosis of depression in at-risk populations, e.g., those with coronary heart disease or who have suffered a stroke.​

Depression is one of the most prevalent and treatable mental disorders and is regularly seen by a broad spectrum of health care providers, including mental health specialists, medical and surgical sub-specialists, and primary care clinicians. There are a number of case-finding instruments for detecting depression in primary care, ranging from two to 28 items in length. Typically, these can be scored as continuous measures of depression severity and also have established cut-points above which the probability of major depression is substantially increased. Scores on these various measures tend to be highly correlated, and it is not evident that any one measure is superior to the others.

The Patient Health Questionnaire (PHQ) is a new instrument for making criteria-based diagnoses of depressive and other mental disorders commonly encountered in primary care. The diagnostic validity of the PHQ has recently been established in two studies involving 3,000 patients in eight primary care clinics and 3,000 patients in seven obstetrics-gynecology clinics.

At nine items, the PHQ depression scale (which we call the “PHQ-9”) is half the length of many other depression measures, has comparable sensitivity and specificity, and consists of the actual nine criteria upon which the diagnosis of DSM-IV depressive disorders is based. The latter feature distinguishes the PHQ-9 from other “two-step” depression measures for which, when scores are high, additional questions must be asked to establish DSM-IV depressive diagnoses.

Reading the PHQ-9​

Major depression is diagnosed if five or more of the nine depressive symptom criteria have been present at least “more than half the days” in the past two weeks, and one of the symptoms is depressed mood or anhedonia. “Other depression” is diagnosed if two, three, or four depressive symptoms have been present at least “more than half the days” in the past two weeks, and one of the symptoms is a depressed mood (“anhedonia”). One of the nine symptom criteria (“thoughts that you would be better off dead or thoughts of hurting yourself in some way”) counts if present at all, regardless of duration. As with the original PRIME-MD, before making a final diagnosis, the clinician is expected to rule out physical causes of depression, normal bereavement, and history of a manic episode.

As a severity measure, the PHQ-9 score can range from 0 to 27, since each of the nine items can be scored from 0 (not at all) to 3 (nearly every day). An item was also added to the end of the diagnostic portion of the PHQ-9 asking patients who checked off any problems on the questionnaire the question, “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?”

PHQ 9 questionnaire

How to score the PHQ-9

Major depressive disorder is suggested if:

  • Of the first nine items, five or more are checked as at least “more than half the days” in the past two weeks
  • Either item 1. or 2. is positive; that is, at least “more than half the days” in the past two weeks

Other depressive syndrome is suggested if:

  • Of the first nine items, 1., 2., or 3. are checked as at least “more than half the days” in the past two weeks
  • Either item 1. or 2. is positive; that is, at least “more than half the days” in the past two weeks

Interpreting PHQ-9 Scores

0-4 Suggests the patient may not need depression treatment

5-14 Indicates mild major depressive disorder. The provider uses clinical judgment about treatment based on patient’s duration of symptoms and functional impairment.

15-19 Moderate-major depressive disorder. Warrants treatment for depression using antidepressants, psychotherapy, or a combination of treatment.

20+ Severe major depressive disorders. Warrants treatment with antidepressants or a combination of antidepressants and psychotherapy. The provider may wish to contact Blue Cross of Idaho for consultation or referral.

To monitor severity over time for newly diagnosed patients or patients in current treatment for depression:

  1. Patients may complete questionnaires as a baseline and at regular intervals (e.g., every two weeks at home) and bring them in at their next appointment for scoring, or they may complete the questionnaire during each scheduled appointment.
  2. Add up totals on each questionnaire
  3. Results may be included in patient files to assist you in setting up a treatment goal, determining the degree of response, as well as guiding treatment intervention

Final diagnosis should be made with a clinical interview and mental status examination including assessment of patient’s level of distress and functional impairment.​

PHQ-9 Management Summary

PHQ 9 questionnaire

Critical Actions

  • Perform suicide risk assessment in patients who respond positively to item nine, “Thoughts that you would be better off dead or of hurting yourself in some way.”
  • Rule out bipolar disorder, normal bereavement, and medical conditions causing depression.

​PHQ-9 (Patient Health Questionnaire-9)

PHQ 9 questionnaire

The PHQ-9 is adapted from the Primary Care Evaluation of Mental Disorders (PRIME-MD) developed by Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues with an educational grant from Pfizer Inc. For research information, contact Dr. Spitzer . No permission is required to reproduce, translate, display or distribute the Patient Health Questionnaire (PHQ).