About the Patient Health Questionnaire-9
PHQ-9, 2001
Primary source
Kroenke K, Spitzer RL, Williams JBW. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606-613.
Who it was built on
Validated on 6,000 adult patients in 8 primary care and 7 obstetrics-gynaecology clinics in the United States (Kroenke and colleagues, 2001).
Source and attribution
- Developed by
- Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc.
- Published
- Journal of General Internal Medicine, September 2001
- Rights
- Free to reproduce, display and translate, as stated by its developers on the questionnaire. The questions are used unchanged.
The score is calculated exactly as published in the scale.
How well it works
In the original study the scale identified 88% of people with major depression (sensitivity) and correctly cleared 88% of people without it (specificity), against a structured interview. Its authors define five symptom levels, minimal to severe. In India, a 2007 multi-centre study validated Hindi and ten other Indian-language versions of the questionnaire family that contains these nine questions against a psychiatrist's diagnosis.
Limitations
A measure of symptom severity over two weeks, not a diagnosis; only a clinician can diagnose depression. The question about self-harm is a screening question: your answer does not measure how likely you are to act on such thoughts, and this site does not assess that. No accuracy figure for the Hindi version in the general population of India is claimed. The Hindi questions are the official translation for India.
Other sources used
The question about difficulty in daily life is printed on the questionnaire itself and is not part of the score.
PHQ and GAD-7 instruction manual, phqscreeners.com
Help contacts: Tele-MANAS, the national mental health helpline of the Ministry of Health and Family Welfare, and 112, the national emergency number of the Ministry of Home Affairs.
Press Information Bureau, Government of India (Tele-MANAS); Ministry of Home Affairs (ERSS-112)