Patient Health Questionnaire-9 (PHQ-9) Adult

10 - item assessment tool for screening, diagnosing, monitoring and measuring the severity of depression.

Audience: PATIENT

Published by ISSWSH

Revision 2 · Published January 30, 2026

Citation

<p>Kroenke, K., Spitzer, R. L., &amp; Williams, J. B. (2001). The PHQ-9: Validity of a brief depression severity measure. <i>Journal of General Internal Medicine</i>, 16(9), 606–613.</p><p>&nbsp;</p><p>PHQ-9 is courtesy of Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc. No permission is required to reproduce, translate, display or distribute.</p>

Summary

Usage&nbsp;&nbsp;Major Depressive Disorder (MDD) is one of the most common mental health disorders in the United States (Maurer, Raymond &amp; Davis, 2018). The Patient Health Questionnaire-9 (PHQ-9) is a 9-item validated screening tool and a symptom severity assessment scale that assists clinicians, typically primary care and mental health settings, with rapid screening for the presence of a clinically significant depressive disorder. The PHQ-9 can assist clinicians in making a diagnosis of depression, quantifying depression symptoms, and monitoring severity and treatment efficacy. Higher scores are associated with decreased functional status and symptom-related difficulties.&nbsp;&nbsp;However, the PHQ-9 is prone to high false-positive rates in primary care settings with one meta-analysis found that only 50% of patients screening positive actually has major depression (Levis et al., 2019). Therefore, when screening for possible depression, the diagnosis ought to be confirmed using DSM-5 criteria. Maurer et al. (2018) summarizes the use of the PHQ-9 as a screening tool and its relationship to the DSM-5 diagnostic criteria for Major Depressive Disorder. Further, root causes and other mental health disorders ought to be considered. PHQ-9 scores &gt; 9 had a sensitivity and specificity of 88% for major depression. A tip sheet highlights additional criteria when using the PHQ-9 to make a tentative depression diagnosis.&nbsp;&nbsp;.&nbsp;Summary&nbsp;&nbsp;The Patient Health Questionnaire-9 (PHQ-9) is a 10-item validated screening tool and a symptom severity assessment scale that assists clinicians, typically primary care and mental health settings, with rapid screening for the presence of a clinically significant depressive disorder. Higher scores are associated with decreased functional status and symptom-related difficulties.&nbsp;The last item, 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, is not included in the score, but is a good indicator of the patient’s global impairment and can be used to track treatment response.&nbsp;Scoring &amp; Recommendations&nbsp;The first 9 questions will answer with one of the following:&nbsp;AnswerPointsNot at all0Several days1More than half the days2Nearly every day3&nbsp;&nbsp;Result&nbsp;RecommendationScoreLevel of depressive symptoms: None (Score 0-4 pts)Support &amp; Monitoring&lt; 5 pointsLevel of depressive symptoms: Mild DepressionConsider further evaluation for possible clinically significant condition.Consider symptom duration and functional impairment to determine treatment strategies.5-9 pointsLevel of depressive symptoms: Moderate DepressionConsider further evaluation for possible clinically significant condition.Consider symptom duration and functional impairment to determine treatment strategies10-14 pointsLevel of depressive symptoms: Moderately Severe DepressionConsider further evaluation for possible clinically significant condition.Consider symptom duration and functional impairment to determine treatment strategiesMay warrant psychotherapy or antidepressant &nbsp;15-19 pointsLevel of depressive symptoms: Severe Depression&nbsp;Consider further evaluation for possible clinically significant condition.Consider symptom duration and functional impairment to determine treatment strategiesMay warrant psychotherapy and antidepressant &nbsp;20-27 points&nbsp;&nbsp;Additional Considerations&nbsp;PHQ-9 scores &gt; 9 had a sensitivity and specificity of 88% for major depression. A tip sheet highlights additional criteria when using the PHQ-9 to make a tentative depression diagnosis. However, when screening for possible depression, the diagnosis ought to be confirmed using DSM-5 criteria. Maurer et al. (2018) summarizes the use of the PHQ-9 as a screening tool and its relationship to the DSM-5 diagnostic criteria for Major Depressive Disorder. Further, root causes and other mental health disorders ought to be considered.&nbsp;&nbsp;Management&nbsp;The clinician ought to rule out physical causes of symptoms, normal bereavement, stress, chronic illness and a history of a manic/hypomanic episode.&nbsp;Some possible root causes of depressionBlood sugar dysregulation and obesity (Lee, 2016; Calkin, 2019)Infection: A few examples -Lyme disease (Bransfield, 2018)Toxoplasma gondii (Hsu, 2014)Sedentary lifestyle (Stancykiewicz, 2019)Sleep deprivation and artificial light exposure (Figueiro, 2011; Gooley, 2011)Social isolation (Uchino, 2006; Cacioppo, 2002)Environmental exposure (A few examples) &nbsp;Indoor mold exposure (Ratnaseelan, 2018; Doi, 2011)Dietary triggers: Consider mold sensitivity from food or the environment. Foods such as coffee, peanuts and grains can have high levels of mold. Many other food sensitivities or allergies can also play a role. A food journal and an elimination diet may help sort this out.Autoimmune DisordersStress&nbsp;Therapeutic modalities that may reduce depression-related symptoms include:Psychotherapy&nbsp;Cognitive behavioral therapySomatic experiencing therapyEye Movement Desensitization and Reprocessing (EMDR)Vagus nerve stimulation&nbsp;Relaxation therapiesMeditation&nbsp;Mindfulness-based stress reduction and breathing techniquesYoga&nbsp;Complementary and alternative medicineAcupunctureMassageSound therapyAromatherapy.

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