Patient Health Questionnaire – Depression (PHQ-9)

The PHQ-9 is the nine item depression subscale of the Patient Health Questionnaire, and is a widely used tool for assisting primary care clinicians in diagnosing depression as well as monitoring treatment.


Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ‐9. Journal of general internal medicine, 16(9), 606-613.