Scale library · Psychology & mental health

PHQ-9 depression scale: Kroenke et al. (2001)

The PHQ-9 is the 9-item depression module of the Patient Health Questionnaire, validated by Kroenke, Spitzer and Williams (2001). Each item matches a DSM-IV criterion for depressive symptoms and asks how often the respondent has been bothered by it over the last 2 weeks. It is short, free and has clear severity cut-offs, so it is widely used to measure depressive symptom severity, often alongside the GAD-7 in theses on the mental health of students, employees and people with chronic illness.

Cite the original, not the blog.

Original English items

Items marked (R) are reverse-coded: recode them before computing reliability or scale scores. Replace bracketed placeholders such as [system] with the name of the system, brand or organization you study.

Depression Severity (PHQ, 9 items)

Code Item wording Reverse-coded
PHQ1 Little interest or pleasure in doing things No
PHQ2 Feeling down, depressed, or hopeless No
PHQ3 Trouble falling or staying asleep, or sleeping too much No
PHQ4 Feeling tired or having little energy No
PHQ5 Poor appetite or overeating No
PHQ6 Feeling bad about yourself—or that you are a failure or have let yourself or your family down No
PHQ7 Trouble concentrating on things, such as reading the newspaper or watching television No
PHQ8 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 No
PHQ9 Thoughts that you would be better off dead or of hurting yourself in some way No

Response scale

4-point frequency scale, not an agreement scale, referring to the last 2 weeks: 0 = Not at all, 1 = Several days, 2 = More than half the days, 3 = Nearly every day. Summing the 9 items gives a total of 0–27; according to the authors, cut-offs of 5, 10, 15 and 20 indicate mild, moderate, moderately severe and severe depression. There are no reverse-coded items. The final question on functional difficulty is not scored.

Licence and permission

According to the PHQ Screeners website and the note printed on the questionnaire, the PHQ-9 was developed by Spitzer, Williams, Kroenke and colleagues with an educational grant from Pfizer and is in the public domain: no permission is required to reproduce, translate, display or distribute it.

Sources (APA 7)

Vietnamese translation

A Vietnamese translation of every item, with sample-size advice and studies that used the scale, is on the Vietnamese page for this scale.

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