Comparison of the usefulness of the PHQ-8 and PHQ-9 for screening for major depressive disorder: Analysis of psychiatric outpatient data

Cheolmin Shin, Seung Hoon Lee, Kyu Man Han, Ho-Kyoung Yoon, Changsu Han

Research output: Contribution to journalArticle

1 Citation (Scopus)


Objective This study aimed to demonstrate that the Patient Health Questionnaire (PHQ)-8 is not less useful than the PHQ-9 as a screening test for major depressive disorder (MDD). Methods We performed a retrospective analysis of 567 patients in psychiatric outpatient units. The Mini International Neuropsychiatric Interview was used to diagnose MDD. We derived the validity and reliability of the PHQ-8 and PHQ-9. To evaluate the ability of the PHQ-8 and PHQ-9 to discriminate MDD, we drew receiver operating characteristic (ROC) curves and compared the areas under the curves (AUCs). Results Of the 567 participants, 207 (36.5%) were diagnosed with MDD. Cronbach’s αs for the PHQ-8 and PHQ-9 were 0.892 and 0.876, respectively. Similar to the PHQ-9, the PHQ-8 was also associated with scores on the Hamilton Depression Rating Scale in a correlation analysis. When we drew ROC curves for the PHQ-8 and PHQ-9, there was no statistically significant difference in the AUCs. With a cutoff score of 10, the PHQ-8 showed a sensitivity of 58.3%, specificity of 83.1%, positive predictive value of 53.4%, and negative predictive value of 85.7%. Conclusion In a psychiatric outpatient sample, the PHQ-8 was as useful as the PHQ-9 for MDD screening.

Original languageEnglish
Pages (from-to)300-305
Number of pages6
JournalPsychiatry Investigation
Issue number4
Publication statusPublished - 2019 Apr 1



  • Depression
  • Major depressive disorder
  • PHQ-8
  • PHQ-9

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry

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