The Patient Health Questionnaire-9 (PHQ-9) is a brief psychological screening instrument designed to measure symptoms of depression in primary care settings. Like the Pittsburgh Sleep Quality Inventory, Big Five Inventory, and Center for Epidemiologic Studies Depression Scale previously reviewed, the PHQ-9 is available to healthcare providers completely free of charge. Pfizer Inc., the legal copyright holder, explicitly states that “no permission [is] required to reproduce, translate, display or distribute [the PHQ-9].” Check the end of this report to download the PHQ-9.
The PHQ-9 is a self-administered depression module of the Patient Health Questionnaire (PHQ). It contains 9 questions that help identify patients with clinically meaningful symptoms of depression. Patient responses are scored 0-3 with 0 representing “not at all” and 3 indicating “nearly every day;” thus, the PHQ-9 contains a total score range of 0-27 . No specific administration time could be found, but a reasonable administration time is approximately 5-10 minutes for cognitively intact patients. PHQ-9 questions are straightforward and pertain to depressive symptoms experienced over the past 2 weeks that include anhedonia, dysphoria, sleep disturbances, fatigue, changes in eating, low self-esteem, concentration difficulties, hypo-or-hyper-active behaviors, and thoughts of suicide or homicide .
The PHQ-9 contains one additional question at the end of the form that asks, “How difficult have these problems made it for you to do your work, take care of things at home, or get along with other people?” Possible answers range from “not difficult at all” to “extremely difficult” .
Scoring can often be accomplished within one minute . Qualitative interpretation of scores is as follows:
Total Score / Qualitative Symptom Classification
1-4 / Minimal depression
5-9 / Mild depression
10-14 / Moderate depression
15-19 / Moderately severe depression
20-27 / Severe depression
Please review the PHQ-9 Administrative Manual for a more in-depth overview of interpretation of patient responses. Clinicians should obviously follow-up with a thorough clinical assessment if depression is detected, particularly if the patient endorses suicidal or homicidal ideation.
The PQH-9 was administered to 6000 patients across 8 primary care and 7 obstetrics-gynecology (OBGYN) clinics. A cut-off score of 10 or greater produced a sensitivity of 88% and specificity of 88% for major depression. Internal reliability estimates range from .86 to 0.89 using Cronbach’s alpha. Two day test-retest reliability is estimated to be .84 with nearly identical mean total scores. The PHQ-9 demonstrated high correlation with another brief depression inventory, Mental Health Inventory (i.e., convergent validity) and higher PHQ-9 scores were related to overall decreased functional status, including more sick days and clinic visits .
The Patient Health Questionnaire-9 is valid, reliable, and cost effective psychological screening instrument for depression. Clinicians may reproduce the PHQ-9 free of charge and without fear of copyright violation. The PHQ-9 is intended to be used by clinicians or researchers in primary care settings. Health/Medical psychologists and physicians may find added confidence in the validity of this instrument given that PHQ-9 normative data is based on large patient samples from primary care and OBGYN settings. The PHQ-9 is useful particularly in busy medical offices or hospitals due to its easy-to-read format and brief administration, scoring, and interpretation.
Download The Patient Health Questionnaire – 9 (PHQ-9)
PHQ-9 Administration/Scoring/Interpretation Manual
 Kroenke, K., Spitzer, R., & Williams, J. (2001). The PHQ-9 validity of a brief depression severity measure. J GEN INTERN MED, 16, 606-613.