Patient Health Questionnaire-9.

PHQ-9

What it measures

Depression severity mapped 1:1 to the nine DSM-IV/DSM-5 MDD criteria (past 2 weeks); doubles as screener and severity monitor

Length and format

9 (+1 functional-impairment item, unscored). 4-point frequency (0-3, not at all to nearly every day), summed 0-27 (self-report questionnaire)

Language versions

80+ languages worldwide (Kroenke 2021 World Psychiatry documents global uptake); validated across most major languages

Normative data

Languages	Countries	Breakdown	Status	Grade	N
de	DE	gender x 7 age bands (14-24...75+), N=5018	COLLECTED	A	5018

Licence

public-domain / open

Licence classification is a research judgement by the catalogue’s authors, not legal advice, and it can be out of date. Confirm terms with the copyright holder or publisher before using an instrument, especially for commercial use.

Reference

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.