Patient Health Questionnaire - 9 (PHQ-9)

The Patient Health Questionnaire - 9 (PHQ-9) is a short self-assessment questionnaire with 9 items that correspond to the DSM-IV diagnostic criteria for depressive disorder. It is a depression module extracted from the full PHQ to determine the severity of depression and depressive symptoms. Items ask about frequency of experience in the past two weeks.

Length of completion

The PHQ-9 takes approximately 3 minutes to complete.

Individualized feedback to the respondent

After scoring the questionnaire, the experimenter will determine the severity of depression or depressive symptoms.

Keywords

Patient Health Questionnaire, PHQ-9, depression, depressive disorder, depressive symptoms

Scoring and interpretation

In determining the PHQ-9 score, each individual symptom is coded as 0, 1, 2, or 3, and the total score obtained by summing the scores ranges from 0 to 27. Higher scores indicate more severe depressive symptoms.

Response Scale

Respondents rate items on a scale of 0 to 3 based on the frequency of their experience in the previous two-week period (0=Not at all, 1=Several days, 2=More than half the days, 3=Almost every day).

References

Daňsová, P., Masopustová, Z., Hanáčková, V., Kicková, K., & Korábová, I. (2016). Metoda Patient Health Questionnaire-9: Česká verze. Československá psychologie, 60(5), 468-481. https://www.researchgate.net/publication/313602110_The_patient_health_questionnaire-9_The_Czech_version

Haddad, M., Walters, P., Phillips, R., Tsakok, J., Williams, P., Mann, A., & Tylee, A. (2013). Detecting depression in patients with coronary heart disease: a diagnostic evaluation of the PHQ-9 and HADS-D in primary care, findings from the UPBEAT-UK study. PloS one, 8(10), e78493. https://doi.org/10.1371/journal.pone.0078493

Kroenke, K., & Spitzer, R. L. (2002). The PHQ-9: A new depression diagnostic and severity measure. Psychiatric Annals, 32(9), 509–515. https://doi.org/10.3928/0048-5713-20020901-06

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