PHQ-9: Patient Health Questionnaire-9

What is the PHQ-9?

The PHQ-9 is a 9-item self-report questionnaire developed by Drs. Robert L. Spitzer, Janet B.W. Williams, and Kurt Kroenke as part of the PRIME-MD diagnostic instrument. It measures the severity of depressive symptoms based on DSM-5 criteria, asking respondents how often they have been bothered by specific problems over the past two weeks.

Taking just 2 to 3 minutes to complete, the PHQ-9 is one of the most validated instruments in behavioral health. It has strong psychometric properties across diverse populations, age groups, and clinical settings. It is freely available for clinical and commercial use with no licensing fee required.

Beyond screening, the PHQ-9 serves as a severity measure that can be administered repeatedly to track treatment response. The APA and numerous clinical practice guidelines recommend it as a core tool for measurement-based care in depression treatment.

PHQ-9 Scoring & Severity Levels

Each of the 9 items is scored on a 4-point Likert scale from 0 (not at all) to 3 (nearly every day). Total scores range from 0 to 27. Higher scores indicate greater depressive symptom severity.

A score of 10 or above is the most commonly used threshold for clinical significance. A 5-point change over time is considered clinically meaningful when tracking treatment response.

PHQ-9 Questions

Respondents rate how often they have been bothered by the following problems over the last 2 weeks:

1. Little interest or pleasure in doing things
2. Feeling down, depressed, or hopeless
3. Trouble falling or staying asleep, or sleeping too much
4. Feeling tired or having little energy
5. Poor appetite or overeating
6. Feeling bad about yourself, or that you are a failure or have let yourself or your family down
7. Trouble concentrating on things, such as reading the newspaper or watching television
8. Moving or speaking so slowly that other people could have noticed, or the opposite: being so fidgety or restless that you have been moving around a lot more than usual
9. Thoughts that you would be better off dead, or of hurting yourself in some way

Item 9 specifically screens for suicidal ideation. Any positive response on this item warrants further clinical assessment regardless of the total score.

Clinical Applications

The PHQ-9 is recommended by the U.S. Preventive Services Task Force (USPSTF) for universal depression screening in primary care and behavioral health settings. Its brevity makes it practical for routine administration, and its sensitivity to change makes it ideal for tracking treatment progress over time.

In measurement-based care, clinicians administer the PHQ-9 at regular intervals, typically before each session or monthly. A change of 5 or more points indicates a clinically meaningful shift, helping therapists make evidence-informed decisions about treatment modifications, referrals, or step-down care.

The PHQ-2, consisting of the first two items (anhedonia and depressed mood), can be used as an ultra-brief screener. A score of 3 or above on the PHQ-2 has good sensitivity for major depression and can be followed by the full PHQ-9 for severity assessment.

The PHQ-9 is also the most frequently used depression measure in clinical research, providing a shared metric across studies and enabling comparison of treatment outcomes.

Reliability & Validity

The PHQ-9 demonstrates excellent internal consistency, with Cronbach's alpha typically ranging from 0.86 to 0.89 across clinical populations. Test-retest reliability is strong, and the measure shows good convergent validity with other established depression instruments.

At the standard cutoff of 10, the PHQ-9 achieves approximately 88% sensitivity and 88% specificity for major depressive disorder. It has been validated across dozens of languages and in populations spanning primary care, psychiatric, medical, and community settings.