Detecting and monitoring depression with a two-item questionnaire (PHQ-2)

Löwe, Bernd; Kroenke, Kurt; Gräfe, Kerstin

doi:10.1016/j.jpsychores.2004.09.006

« Previous Next »Journal of Psychosomatic Research
Volume 58, Issue 2 , Pages 163-171, February 2005

Detecting and monitoring depression with a two-item questionnaire (PHQ-2)

Bernd Löwe
- Department of General Internal and Psychosomatic Medicine, University of Heidelberg Medical Center, Im Neuenheimer Feld 410, Heidelberg D-69120, Heidelberg, Germany
- Regenstrief Institute, Indiana University School of Medicine, 1050 Wishard Boulevard, Indianapolis, IN 46202, U.S.A.
- Corresponding author. Department of General Internal and Psychosomatic Medicine, University of Heidelberg Medical Center, Im Neuenheimer Feld 410, Heidelberg D-69120, Heidelberg, Germany. Tel.: +49 6221 568999; fax: +49 6221 565749.
Kurt Kroenke
- Regenstrief Institute, Indiana University School of Medicine, 1050 Wishard Boulevard, Indianapolis, IN 46202, U.S.A.
Kerstin Gräfe
- Department of General Internal and Psychosomatic Medicine, University of Heidelberg Medical Center, Im Neuenheimer Feld 410, Heidelberg D-69120, Heidelberg, Germany

Received 30 March 2004; accepted 22 September 2004.

Abstract

Objective

This study evaluates the two-item Patient Health Questionnaire (PHQ-2) as a measure for diagnosing and monitoring depression.

Methods

We assessed construct validity in a cross-sectional sample of 1619 medical outpatients (mean age 43±14 years, 64% female) by comparing the PHQ-2 to four longer self-report questionnaires. Criterion validity was established in a subsample of 520 participants with reference to the Structured Clinical Interview for DSM-IV (SCID). Sensitivity to change was investigated in a prospective study of 167 patients who completed the SCID both at baseline and the 1-year follow-up.

Results

With reference to the SCID, the PHQ-2 had a sensitivity of 87% and a specificity of 78% for major depressive disorder and a sensitivity of 79% and a specificity of 86% for any depressive disorder. Its diagnostic performance was comparable with that of longer depression scales. PHQ-2 change scores accurately reflected improved, unchanged, and deteriorated depression outcomes.

Conclusion

The PHQ-2 performed favorably with respect to a standard diagnostic interview, as well as established depression scales and proved sensitive to change. Thus, the PHQ-2 appears promising as a brief multipurpose measure for detecting depression, grading its severity, and monitoring outcomes over time.

Keywords: Depressive disorders, Diagnosis, Questionnaires, Patient Health Questionnaire (PHQ-2), Reproducibility of results, Sensitivity and specificity