PHQ‑9: Patient Health Questionnaire‑9

The Patient Health Questionnaire‑9 (PHQ‑9) is a brief, self‑administered questionnaire used worldwide to assess the presence and severity of depressive symptoms. Each of its nine items corresponds to diagnostic criteria for major depressive disorder in the DSM‑5. Because it is concise and easy to score, the PHQ‑9 is widely adopted in primary care, mental health clinics and research studies.

DSM-5 Alignment: The PHQ-9 directly maps to DSM-5 criteria for major depressive disorder. Each question assesses one of the nine diagnostic symptoms: depressed mood, anhedonia (loss of interest/pleasure), sleep disturbance, fatigue, appetite changes, feelings of worthlessness or guilt, concentration difficulties, psychomotor changes and suicidal ideation. This alignment makes the PHQ-9 both a screening tool and a severity measure that can track symptom changes during treatment.

Evidence & validation: Research involving thousands of patients has shown that the PHQ‑9 is both reliable and valid. A score of 10 or greater has been found to have 88% sensitivity and 88% specificity for major depression. The tool's cut‑off scores (5, 10, 15 and 20) correspond to mild, moderate, moderately severe and severe depression.

Why use it? Depression affects millions of people around the globe, yet many go undiagnosed. The PHQ‑9 empowers you to reflect on your mental health and quantify your symptoms. Regular use can help you notice changes over time and facilitate discussions with healthcare professionals.

Alternatives: For rapid initial screening, healthcare providers sometimes use the PHQ‑2, which consists of the first two questions of the PHQ‑9. A positive PHQ‑2 should be followed by the full PHQ‑9. There are also other instruments such as the Beck Depression Inventory (BDI) and the Hamilton Rating Scale for Depression, but these often require administration by a clinician.

Important disclaimer: The PHQ‑9 is a screening tool. It cannot diagnose depression. If your responses indicate moderate or severe symptoms or you have any thoughts of self‑harm, seek professional help immediately. In the U.S., you can call the 988 Suicide & Crisis Lifeline.

Reference: View the original PHQ-9 questionnaire (PDF) from the American Psychological Association.

You'll answer nine questions about how often you've experienced certain symptoms during the past two weeks. Each response is scored from 0 (Not at all) to 3 (Nearly every day). After completing the questionnaire, your responses are summed to produce a total score between 0 and 27. The higher the score, the more severe your depressive symptoms are likely to be.

The PHQ‑9 covers core symptoms such as low mood, loss of interest, sleep and appetite changes, fatigue, concentration problems, feelings of guilt or worthlessness, psychomotor changes and suicidal thoughts. Completing the questionnaire typically takes just a couple of minutes.