Definition
The PHQ-9 (Patient Health Questionnaire-9) is a nine-item self-report instrument designed to screen for and monitor major depression symptoms. Its items correspond directly to the nine diagnostic criteria for major depressive episode in DSM-5. Each item is scored from 0 (not at all) to 3 (nearly every day), with a total score of 0 to 27.
Cut-off scores
| Score | Severity |
|---|---|
| 0-4 | Minimal or none |
| 5-9 | Mild depression |
| 10-14 | Moderate depression |
| 15-19 | Moderately severe depression |
| 20-27 | Severe depression |
A cut-off of 10 or above has 88% sensitivity and 88% specificity for major depressive episode (Kroenke, Spitzer & Williams, 2001).
When it is used
- At the start of a therapeutic process when the primary complaint includes depressed mood, anhedonia, fatigue, or loss of energy.
- In periodic follow-up of clients with an established depressive diagnosis to monitor treatment response.
- Whenever there are verbalizations of thoughts of death or wishes to not exist (item 9 specifically assesses this risk).
- In primary care, psychiatry, clinical social work, and psychology.
When it is not sufficient on its own
The PHQ-9 does not diagnose depression. It screens. An elevated score indicates that a full clinical evaluation is warranted. It does not replace the diagnostic interview or clinical judgment. It is also not designed to evaluate bipolar disorders (a high score during a hypomanic episode could produce a false positive for depression).
Item 9: suicide risk detection
Item 9 specifically asks about thoughts of death or self-harm. Any response greater than zero activates the need for a more detailed risk assessment within the same session. A positive response does not equal imminent risk. It is information the clinician must explore.
Example of use in session
A therapist administers the PHQ-9 in the first session. The client scores 13 (moderate), with item 9 at 1 ("several days"). The therapist explores item 9 directly, documenting the exploration in the clinical note. The score of 13 points toward a diagnosis of moderate depressive episode pending full evaluation.
How CauceOS supports this
CauceOS can record scale results administered in session and link them automatically to the Objective section of the SOAP note or to the assessment field of the post-session report. Item 9 with a score greater than zero triggers an attention note in the professional's dashboard.
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, 606-613.
- Spitzer, R. L., Kroenke, K., & Williams, J. B. W. (1999). Validation and utility of a self-report version of PRIME-MD. JAMA, 282(18), 1737-1744.
- American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.).
Related terms
- GAD-7: complementary scale for anxiety assessment
- PCL-5: scale for PTSD symptoms
- Crisis detection: protocol when item 9 is positive