PHQ-9
Quantifies depression symptom burden according to DSM criteria, assists in monitoring therapeutic response, and includes screening for suicidal ideation.
Little interest or pleasure in doing things
Over the last 2 weeks, how often have you been bothered by this problem?
About the PHQ-9
Validated 9-item screening and severity measure for depressive symptoms over the preceding two weeks.
Scoring Methodology & Interpretation
The PHQ-9 uses a validated sum algorithm with predefined clinical cutoffs established in peer-reviewed derivation and validation cohorts:
| Score Range | Severity Classification | Clinical Interpretation |
|---|---|---|
| 0 – 4 | Minimal or No Depressive Symptoms | Scores 0–4 suggest absence of significant depression. |
| 5 – 9 | Mild Depressive Symptoms | Scores 5–9 indicate mild depressive symptoms. |
| 10 – 14 | Moderate Depressive Symptoms | Scores 10–14 represent the standard clinical cutoff (sensitivity 88%, specificity 88%). |
| 15 – 19 | Moderately Severe Depressive Symptoms | Scores 15–19 warrant active treatment planning. |
| 20 – 27 | Severe Depressive Symptoms | Scores 20–27 represent severe depressive disorder. |
Clinical Pearls & Considerations
- A change of 5 points on repeat testing is considered clinically meaningful (minimal clinically important difference).
- Can be self-administered or administered by a clinician.
Developed by Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues with support from Pfizer Inc. Pfizer offers the PHQ series without a formal permission request, subject to its published terms of use.
This instrument is designed for educational, informational, and clinical reference purposes. Screening scores do not constitute a definitive medical diagnosis. Individual clinical management must integrate full diagnostic history, physical examination, and laboratory data by a licensed healthcare professional.
- The PHQ-9 is a screening instrument, not a diagnostic confirmation.
- Somatic symptoms (fatigue, sleep changes, appetite changes) can stem from primary medical conditions like hypothyroidism or chronic pain.
- Positive responses to Item 9 mandate immediate clinical assessment for suicidal ideation and intent.
Evidence & Primary Literature Citations
- Key Validation StudyThe PHQ-9: validity of a brief depression severity measure.Kroenke K, Spitzer RL, Williams JB. J Gen Intern Med. 2001;16:606-613.
- The Patient Health Questionnaire Somatic, Anxiety, and Depressive Symptom Scales: a systematic review.Kroenke K, Spitzer RL, Williams JB, Löwe B. Gen Hosp Psychiatry. 2010;32:345-359.