Patient Health Questionnaire–9 (PHQ-9)

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The PHQ-9 is a widely used, 9-item self-report questionnaire designed to assess depressive symptom severity based on DSM-5 diagnostic criteria for Major Depressive Disorder. It is one of the most commonly used tools in both primary care and mental health settings due to its brevity, clarity, and clinical utility.

Developed by Drs. Robert L. Spitzer, Janet B.W. Williams, and Kurt Kroenke, the PHQ-9 can be used to screen for depression, monitor symptom change, and inform treatment planning.

Recommended Frequency: Every 2 weeks during treatment for depression; at intake and follow-up visits

About the PHQ-9

Each of the 9 questions corresponds to a symptom criterion for Major Depressive Disorder, including:

  • Depressed mood
  • Anhedonia (loss of interest or pleasure)
  • Sleep disturbance
  • Fatigue
  • Appetite changes
  • Feelings of worthlessness or guilt
  • Trouble concentrating
  • Psychomotor changes
  • Suicidal thoughts

Respondents rate how often they’ve been bothered by each symptom over the past 2 weeks, using a 4-point scale:

0 – Not at all
1 – Several days
2 – More than half the days
3 – Nearly every day

Who is the PHQ-9 For?

The PHQ-9 is validated for use with adults and adolescents (12+) and is widely used in:

  • Primary care, psychiatry, and general mental health settings
  • Clients reporting mood changes, energy loss, or withdrawal
  • Ongoing treatment to monitor clinical response
  • Screening efforts in schools, workplaces, and community programs

The Scale

Each item is scored from 0 to 3, for a total possible score of 0 to 27.

The final 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?”) is not included in the total score, but helps assess functional impairment—a key factor in diagnosing depression.

Scoring the PHQ-9

0–4 Minimal: Monitor, no treatment required

5–9 Mild: Supportive interventions or watchful waiting

10–14 Moderate: Active treatment recommended

15–19 Moderately severe: Consider medication, therapy, or both

20–27 Severe: Immediate and intensive intervention recommended

HiBoop automatically flags scores of 10 or more, and separately alerts clinicians to any non-zero response to item 9(suicidal ideation).

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TIP FOR PRACTICE

A high PHQ-9 score offers an entry point, not a conclusion. Use it to start the conversation:

“These scores suggest you’ve been struggling lately—can we talk more about what that looks like day to day?”

The PHQ-9 in Practice

Use cases include:

  • Screening for depression in medical or therapeutic settings
  • Tracking treatment progress over time
  • Detecting risk of self-harm or suicidality via item 9
  • Pairing with anxiety or trauma assessments (e.g., GAD-7, PCL-5) for a full diagnostic picture

HiBoop allows PHQ-9 scores to be tracked longitudinally and visualized alongside other measures in a client’s profile. Alerts can be configured based on severity thresholds or sharp score increases.

Copyright

The PHQ-9 was developed by Drs. Spitzer, Williams, and Kroenke. It is freely available for clinical use and part of the public domain through the Pfizer-supported PHQ family of assessments.

References

  • Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9: Validity of a brief depression severity measure.Journal of General Internal Medicine, 16(9), 606–613.
  • American Psychiatric Association. DSM-5 Criteria for Major Depressive Disorder.

Disclaimer

The PHQ-9 is a screening and monitoring tool, not a standalone diagnostic assessment. Clinical judgment and full evaluation are required for diagnosis and treatment decisions.

Permissions

The PHQ-9 was developed by Drs. Spitzer, Williams, and Kroenke. It is freely available for clinical use and part of the public domain through the Pfizer-supported PHQ family of assessments. See Pfizer Press Release

Frequently Asked Questions

  • Can this be completed remotely?

    Yes. HiBoop supports secure digital administration with automatic scoring and clinician alerts.

  • How often should the PHQ-9 be used?

    Every 2 weeks is standard in active treatment, or at each session in brief therapy settings.

  • What does a non-zero score on question 9 mean?

    Any answer other than “Not at all” to item 9 (suicidal thoughts) should prompt follow-up questions and, if needed, a risk assessment.

  • Can the PHQ-9 be used with teens?

    Yes. It is validated for use in adolescents 12 and up.

  • Is the PHQ-9 a diagnostic tool?

    No. It supports diagnosis but should always be used alongside a full clinical assessment.