PatientPlus articles are written for doctors and so the language can be technical. However, some people find that they add depth to the articles found in the other sections of this website which are written for non-medical people.

Patient Health Questionnaire (PHQ-9)

This easy to use patient questionnaire is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders.¹ The PHQ-9 is the depression module, which scores each of the 9 DSM-IV criteria as "0" (not at all) to "3" (nearly every day). It has been validated for use in Primary Care.²

Validity has been assessed against an independent structured mental health professional (MHP) interview. PHQ-9 score ≥10 had a sensitivity of 88% and a specificity of 88% for major depression.^1,2 It can even be used over the telephone.³

Depression Severity: 0-4 None, 5-9 Mild depression, 10-14 Moderate depression, 15-19 Moderately severe depression, 20-27 Severe depression.

References, footnotes and further reading

1. Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001 Sep;16(9):606-13.
2. Dietrich AJ, Oxman TE, Burns MR, Winchell CW, Chin T. Application of a depression management office system in community practice: a demonstration. J Am Board Fam Pract. 2003 Mar-Apr;16(2):107-14.
3. Pinto-Meza A, Serrano-Blanco A, Penarrubia MT, Blanco E, Haro JM. Assessing depression in primary care with the PHQ-9: can it be carried out over the telephone? J Gen Intern Med. 2005 Aug;20(8):738-42.

Acknowledgements PHQ9 Copyright ©Pfizer. Reprinted with permission, courtesy of Pfizer Limited. PRIME-MD ® is a trademark of Pfizer