Patient Health Questionnaire - 9 (PHQ-9)

Assessment Rating:
A – Psychometrics Well-Demonstrated
See entire scale

Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke & colleagues

Description / Purpose:

The PHQ-9 is the nine item depression screening scale of the Patient Health Questionnaire. 

Note: The PHQ-9 was not responsive to the CEBC's inquiry. The following information was obtained from publicly available sources.

It is a tool for assisting primary care clinicians in diagnosing depression as well as selecting and monitoring treatment. The primary care clinician and/or office staff should discuss with the patient the reasons for completing the questionnaire and how to fill it out.

Target Population: Adolescents 13-17

Time to Administer: Less than 5 minutes

Completed By: Patients in a primary care setting

Modalities Available: Pen and paper

Scoring Information: Scored by the primary care clinician and/or office staff

Languages Available: English

Training Requirements for Intended Users: None

Availability: Can be accessed for free at The site also provides comprehensive instruction documents, articles, a bibliography and a direct point of contact e-mail address.

Contact Information

Company: Pfizer

Summary of Relevant Psychometric Research

This tool has received the Measurement Tools Rating of "A – Psychometrics Well-Demonstrated" based on the published, peer-reviewed research available. The tool must have 2 or more published, peer-reviewed studies that have established the measure’s psychometrics (e.g., reliability and validity, sensitivity and specificity, etc.). Please see the Measurement Tools Rating Scale for more information.

Show relevant research...

Ganguly, S., Samanta, M., Roy, P., Chatterjee, S., Kaplan, D. W., & Basu, B. (2013). Patient Health Questionnaire-9 as an effective tool for screening of depression among Indian adolescents. Journal of Adolescent Health, 52(5), 546-551.


Participants — 233 adolescent students aged 14 to18 years

Race/Ethnicity — 100% Indian


This article discusses the diagnostic accuracy, reliability, and validity of the Patient Health Questionnaire - 9 (PHQ-9) when pediatricians use it among Indian adolescents. Results indicate a total of 31 students (13.3%) had a form of depression on psychiatric interview. A PHQ-9 score of 5 was ideal for screening (sensitivity, 87.1%; specificity, 79.7%). In addition to good content validity, PHQ-9 had good 1-month test-retest reliability (r = .875) and internal consistency (Cronbach’s a = .835). There was high convergent validity with the Beck Depression Inventory (r = .76; p = .001). The concordance rate between the PHQ-9 threshold score of 10 and the International Classification of Diseases, 10th Revision based diagnosis was good (Cohen’s k = .62). The area under the receiver operating characteristic curve for PHQ-9 was .939.

Richardson, L. P., McCauley, E., Grossman, D. C., McCarty, C. A., Richards, J., Russo, J. E., ... & Katon, W. (2010). Evaluation of the Patient Health Questionnaire-9 Item for detecting major depression among adolescents. Pediatrics, 126(6), 1117-1123.


Participants — 442 youth aged 13 to17 years

Race/Ethnicity — Not Specified


The purpose of this study was to examine the performance characteristics and validity of the Patient Health Questionnaire-9 Item (PHQ-9) as a screening tool for depression among adolescents. The PHQ-9 was completed by youth who were enrolled in a large health care– delivery system and participated in a study on depression outcomes. Criterion validity and performance characteristics were assessed against an independent structured mental health interview (the Child Diagnostic Interview Schedule [DISC-IV]). Construct validity was tested by examining associations between the PHQ-9 and a self-report measure of functional impairment, as well as parental reports of child psychosocial impairment and internalizing symptoms. Results indicate A PHQ-9 score of 11 or more had a sensitivity of 89.5% and a specificity of 77.5% for detecting youth who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for major depression on the DISC-IV. Receiver-operator-curve analysis revealed that the PHQ-9 had an area under the curve of 0.88 (95% confidence interval: 0.82– 0.94), and the cut point of 11 was optimal for maximizing sensitivity without loss of specificity. Increasing PHQ-9 scores were significantly correlated with increasing levels of functional impairment, as well as parental report of internalizing symptoms and psychosocial problems.

Allgaier, A. K., Pietsch, K., Frühe, B., Sigl‐Glöckner, J., & Schulte‐Körne, G. (2012). Screening for depression in adolescents: validity of the patient health questionnaire in pediatric care. Depression and anxiety, 29(10), 906-913.


Participants — 322 youth aged 13 to16 years

Race/Ethnicity — 100% German


This study examines the criterion validity of the Patient Health Questionnaire 9-item (PHQ-9) and 2-item (PHQ-2) version as a depression screening instrument for adolescents. Adolescents were recruited from pediatric hospitals. Criterion validity of the PHQ-9 and PHQ-2 was assessed against diagnoses of any depressive disorder provided by a structured diagnostic interview. Areas under the receiver operating characteristics curve (AUCs) and sensitivities and specificities at optimal cutoff points were computed for both versions of the PHQ. Besides the dimensional algorithm, a categorical algorithm was applied for the PHQ-9. Validity measures of both scoring procedures of the PHQ-9 as well as PHQ-2 were compared statistically. In addition, unaided clinical depression diagnoses by the attending pediatricians were evaluated. Results indicate the AUC of the PHQ-9 (93.2%) was significantly higher than that of the PHQ-2 (87.2%). At optimal cutoffs, there was no significant difference in sensitivity (PHQ-9: 90.0%, PHQ-2: 85.0%), but in specificity (PHQ-9: 86.5%, PHQ-2: 79.4%). Although the categorical algorithm of the PHQ-9 was most specific (94.7%), sensitivity was just above chance (52.5%). The unaided clinical diagnoses yielded a sensitivity of 12.5% and a specificity of 96.0%.

Date Reviewed: February 2015 (Originally reviewed in February 2015)