Patient Health Questionnaire-9

PHQ-9

psychologyhealth sciencesFree for research use

A 9-item self-report instrument for screening and measuring the severity of depression, based on DSM diagnostic criteria.

Items

Response format

4-point frequency scale

Version

1.0

Ready-to-cite methods sentence

Depressive symptoms were measured using the PHQ-9 (Kroenke et al., 2001), a 9-item self-report instrument with strong internal consistency (α = .89). Higher scores indicate greater depression severity.

Reliability & validation

Validation population

Primary care patients

Test–retest

0.84

Cronbach's α

0.89

Response anchors

Not at all · Several days · More than half the days · Nearly every day

Known limitations

Validated primarily in primary care settings. A score above 10 warrants clinical follow-up but does not constitute a diagnosis. Item 9 (suicidal ideation) requires clinical judgment independent of total score.

Original citation

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(9), 606-613.

https://doi.org/10.1046/j.1525-1497.2001.016009606.x

Use PHQ-9 in Folio Surveyor

Add it to a study with the full items, scoring, and analysis built in.

Open Surveyor

Library entry verified January 2024. Metadata is provided for reference; item wording is available inside Folio Surveyor, subject to each instrument's licensing.