Psychometric properties and clinical utility of brief measures of depression, anxiety, and general distress: the PHQ-2, GAD-2, and K-6

Lauren G. Staples*, Blake F. Dear, Milena Gandy, Vincent Fogliati, Rhiannon Fogliati, Eyal Karin, Olav Nielssen, Nickolai Titov

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

51 Citations (Scopus)
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Objective: The nine-item Patient Health Questionnaire (PHQ-9), seven-item Generalized Anxiety Disorder scale (GAD-7), and ten-item Kessler Psychological Distress Scale (K-10) are valid and reliable measures of depression, anxiety and general distress. However, the time required in their administration may limit their use in routine care. This study examines the utility of shorter versions (PHQ-2, GAD-2, and K-6) as screening instruments and measures of treatment response. Method: Data from research trial participants (n = 993) receiving internet-delivered cognitive behaviour therapy (iCBT) were analysed to establish discriminant validity of the short versions. Mini International Neuropsychiatric Interview (MINI) diagnoses were used as comparators. Criterion group validity, test–retest reliability, internal consistency, and responsiveness to treatment changes were examined. Analyses were replicated using data from patients receiving iCBT in routine care (n = 1389). Results: Discriminant validity was excellent for the PHQ-2, and acceptable for the GAD-2 and K-6. Acceptable sensitivity and specificity were identified at a threshold of ≥3 for the PHQ-2 and GAD-2, and ≥14 for the K-6. The short versions were sensitive to treatment change. Conclusion: The PHQ-2, GAD-2 and K-6 are useful screeners and efficient measures of treatment progress and outcomes in routine clinical care.

Original languageEnglish
Pages (from-to)13-18
Number of pages6
JournalGeneral Hospital Psychiatry
Publication statusPublished - Jan 2019

Bibliographical note

Copyright the Author(s) 2018. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


  • Patient Health Questionnaire
  • Generalized Anxiety Disorder Questionnaire
  • Kessler Psychological Distress Scale
  • internet
  • Cognitive Behavior Therapy
  • treatment change


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