Question 1

What are the clinical cutoff scores for the PHQ-9?

Accepted Answer

The PHQ-9 uses cutoff scores of 5, 10, 15, and 20 to define mild, moderate, moderately severe, and severe depression, respectively. A score of 10 or greater is the standard threshold for identifying clinically significant depression, with 88% sensitivity and 88% specificity for major depression validated against structured psychiatric interviews (Kroenke et al., 2001, J Gen Intern Med).

Question 2

Can the PHQ-9 be used with adolescents?

Accepted Answer

Yes. The PHQ-9 has been validated for use in adolescents aged 12-17 years. The PHQ-A (Adolescent version) uses the same nine items with minor wording modifications. The USPSTF recommends depression screening for adolescents aged 12-18, and the PHQ-9/PHQ-A is among the recommended instruments for this purpose.

Question 3

How does the PHQ-9 compare to the BDI-II for measuring depression?

Accepted Answer

Both are well-validated self-report depression measures. The PHQ-9 is shorter (9 vs. 21 items), free to use, and directly maps to DSM criteria, making it preferred in primary care and research settings. The BDI-II provides more granular symptom assessment and is widely used in psychological practice, but requires a commercial license. Correlation between the two instruments typically ranges from r = 0.73-0.84.

Question 4

How should clinicians handle a positive response on question 9 (suicidal ideation)?

Accepted Answer

Any positive response to item 9 ('Thoughts that you would be better off dead or of hurting yourself') warrants immediate further assessment regardless of the total score. Clinicians should conduct a thorough suicide risk evaluation including intent, plan, and access to means. Item 9 is a screening flag, not a comprehensive suicide risk tool, and positive endorsement should trigger follow-up with a validated instrument such as the Columbia Suicide Severity Rating Scale (C-SSRS).

Question 5

What PHQ-9 score change indicates meaningful clinical improvement?

Accepted Answer

A reduction of 5 or more points on the PHQ-9 is generally considered a clinically meaningful change, while a 50% or greater reduction from baseline is commonly used to define treatment response. These thresholds were established in the original Kroenke et al. (2001) validation study and have been confirmed in subsequent research across diverse clinical populations.

Question 6

What does my PHQ-9 score mean?

Accepted Answer

We have a detailed scoring guide that explains how to interpret your PHQ-9 results, including severity ranges and recommended clinical actions. Read our full scoring guide.

PHQ-9: Patient Health Questionnaire-9

Take the PHQ-9 assessment. Most widely used 9-item depression screening tool worldwide. Free, evidence-based, DSM-aligned depression severity measure.

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