PHQ-9 Depression Screening Calculator

Administer and score the Patient Health Questionnaire-9 (PHQ-9) for depression screening and severity assessment.

Instructions

Ask the patient: "Over the past 2 weeks, how often have you been bothered by the following problems?"

1. Little interest or pleasure in doing things?

2. Feeling down, depressed, or hopeless?

3. Trouble falling or staying asleep, or sleeping too much?

4. Feeling tired or having little energy?

5. Poor appetite or overeating?

6. Feeling bad about yourself — or that you are a failure or have let yourself or your family down?

7. Trouble concentrating on things, such as reading the newspaper or watching television?

8. Moving or speaking so slowly that other people could have noticed? Or so fidgety or restless that you have been moving a lot more than usual?

9. Thoughts that you would be better off dead, or thoughts of hurting yourself in some way?

10. If you checked any problems, how difficult have these made it for you to do your work, take care of things at home, or get along with other people?

* This item assesses functional impairment but is not included in the total score

Results

Enter values and click Calculate to see results

Methodology

The PHQ-9 is based on the 9 DSM-5 criteria for major depressive disorder. Each question assesses symptom frequency over the past 2 weeks using a 4-point scale (0=not at all, 1=several days, 2=more than half the days, 3=nearly every day). Total scores range from 0-27, with established cut-points for depression severity levels. Question 9 specifically assesses suicidal ideation and requires immediate attention if positive.

About This Calculator

1. What is the PHQ-9 and how does it work?

The PHQ-9 (Patient Health Questionnaire-9) is a validated screening tool for depression based on the 9 DSM-5 criteria for major depressive disorder. Each question is scored 0-3 based on frequency of symptoms over the past 2 weeks, with total scores ranging from 0-27. PHQ-9 ≥10 has approximately 88% sensitivity and 88% specificity for major depression.

2. How are PHQ-9 scores interpreted and what is the diagnostic algorithm?

Validated cut points: 0-4 (minimal), 5-9 (mild), 10-14 (moderate), 15-19 (moderately severe), 20-27 (severe). The diagnostic algorithm for provisional MDD requires ≥5 items scored ≥2 ('more than half the days') AND either Q1 or Q2 ≥2, with Q9 counted if ≥1. Screen-positive threshold is PHQ-9 ≥10.

3. What is the safety rule for item 9 (suicidal thoughts)?

Any Q9 {'>'} 0 requires immediate suicide risk assessment by a competent clinician, regardless of total score. This is a critical safety rule. Never ignore suicidal ideation - ensure immediate professional evaluation and safety planning. Contact emergency services if there's imminent risk.

4. How is the PHQ-9 used for treatment monitoring?

Treatment monitoring definitions: Response = ≥50% reduction from baseline; Remission = total score <5; MCID (minimally clinically important difference) ≈ 5-point drop. Regular monitoring every 2-4 weeks during treatment helps track progress and adjust interventions.

5. What are the USPSTF recommendations for depression screening?

The USPSTF recommends adult depression screening when systems exist for accurate diagnosis, effective treatment, and follow-up. Screening should be part of a comprehensive approach that includes proper clinical evaluation, treatment resources, and monitoring capabilities.

6. What are the evidence-based limitations of the PHQ-9?

The PHQ-9 is a screening tool, not diagnostic. Limitations include: self-reported symptoms may be under/over-reported, doesn't assess all mental health aspects, cultural factors may affect responses, requires clinical interpretation in context, and may not capture subsyndromal depression. Always use as part of comprehensive clinical assessment.