PHQ-9
Patient Health Questionnaire-9
Nine-item self-report screen and severity measure for depression, mapped 1:1 to DSM criteria.
What it measures
Frequency over the past two weeks of each of the nine DSM-5 symptoms of major depressive disorder. Item 9 separately assesses passive suicidal ideation and self-harm thoughts. A tenth functional impact question is sometimes included.
Scoring and bands
Cutoffs
A score of ≥10 has 88% sensitivity and 88% specificity for major depression in primary care samples. A 5-point change is generally considered clinically meaningful.
How to talk about the score
Share the total and what the band means, then talk about which items drove the score. Always discuss item 9 directly — never skip it. Frame the measure as a tool you use with everyone, not a verdict on the person.
Limitations
- Self-report — vulnerable to under- or over-reporting
- Two-week window may miss episodic patterns
- Doesn't distinguish unipolar from bipolar depression
- Item 9 is a screen, not a risk assessment by itself
Best used for
- Routine intake screening
- Session-to-session tracking
- Treatment response monitoring
- Primary-care depression screening
FAQ
What if a client scores 0 on item 9 but presents with risk?
Trust the clinical picture. The PHQ-9 is a screen, not a risk assessment. Conduct a full safety assessment any time clinical signals warrant it, regardless of the item-9 score.
How often should I re-administer?
Weekly to monthly is typical during active treatment. The measure is sensitive enough to detect change at that interval and brief enough to fit into a session.
Is the PHQ-9 valid for adolescents?
The PHQ-A is the adolescent-adapted version (ages 11–17) and is preferred for that age group. The standard PHQ-9 can be used 12+ in many settings.