How do you score the Patient Health Questionnaire-9 (PHQ-9) for a patient?

How to Score the PHQ-9

The PHQ-9 is scored by summing all 9 items, each rated 0-3 based on symptom frequency over the past 2 weeks, yielding a total score of 0-27, with scores of 5,10,15, and 20 representing mild, moderate, moderately severe, and severe depression respectively. 1

Scoring Methodology

Basic Calculation

• Each of the 9 items corresponds to a DSM-IV criterion for major depression and is scored on a 4-point scale 1:
  • 0 = "Not at all"
  • 1 = "Several days"
  • 2 = "More than half the days"
  • 3 = "Nearly every day"
• Simply add all 9 item scores together to obtain the total score (range: 0-27) 1

The 9 Items Being Scored

• The items assess: anhedonia, depressed mood, sleep problems, low energy, appetite changes, low self-view, concentration difficulties, psychomotor retardation or agitation, and thoughts of self-harm 2

Score Interpretation

Severity Categories

• 0-4: Minimal or no depression 1
• 5-9: Mild depression 1
• 10-14: Moderate depression 1
• 15-19: Moderately severe depression 1
• 20-27: Severe depression 1

Clinical Action Thresholds

• Score 1-7: No or minimal symptoms; no formal treatment needed, but verify effective coping skills and social support 2
• Score 8-14: Moderate symptomatology with mild to moderate functional impairment; seek consultation from psychology or psychiatry for diagnostic determination 2
• Score 15-27: Most depressive symptoms present with moderate to marked functional interference; immediate referral to psychology and/or psychiatry for diagnosis and treatment 2

Critical Safety Assessment

Item 9 Requires Special Attention

• Item 9 asks about thoughts of self-harm ("Thoughts that you would be better off dead or hurting yourself in some way") 2
• If the patient endorses ANY frequency on this item (score ≥1), immediate referral for emergency psychiatric evaluation by a licensed mental health professional is mandatory, regardless of the total PHQ-9 score 2, 3
• Never omit Item 9 from scoring, as doing so artificially lowers the total score and causes patients to appear less symptomatic than they actually are, while weakening predictive validity 2, 4

Two-Stage Screening Approach (Optional)

Initial PHQ-2 Screen

• Some settings use a two-item version first, asking only about anhedonia and depressed mood 2
• If the patient scores 0 or 1 on these two items combined, no further screening is needed 2
• If the patient scores 2 or 3 (meaning either item was endorsed as occurring "more than half the days" or "nearly every day"), complete the remaining 7 items of the full PHQ-9 2
• This approach reduces burden, as only 25-30% of patients need to complete all 9 items 2

Optimal Cutoff Scores

Context-Dependent Thresholds

• The traditional cutoff of ≥10 has sensitivity and specificity of 88% for major depression in primary care settings 1
• For cancer outpatients specifically, a lower cutoff of ≥8 demonstrates better diagnostic accuracy 2, 5
• Meta-analysis supports that cutoff scores between 8-11 all have acceptable diagnostic properties, with no substantial differences in pooled sensitivity and specificity 5

Common Pitfalls to Avoid

Scoring Errors

• Do not use the PHQ-9 score alone as a diagnosis—it is a screening tool that requires clinical assessment of pertinent history, risk factors, sociodemographic factors, psychiatric comorbidities, duration of symptoms, and functional impairment 2, 4
• Do not skip Item 9 to avoid discussing self-harm, as this creates false reassurance and misses critical safety issues 2, 4
• Do not assume a low total score means no suicide risk—a patient can score 7 overall but still endorse Item 9, requiring immediate intervention 6

Implementation Mistakes

• Never administer the PHQ-9 without established pathways for managing positive screens, as screening without clear protocols for diagnostic evaluation and treatment does not improve outcomes 4
• The 2-week timeframe may not capture episodic or fluctuating symptoms adequately 4
• The PHQ-9 was validated as a periodic assessment tool, not a daily symptom tracker 4

PHQ-8 Alternative

When Item 9 Is Omitted

• The PHQ-8 excludes Item 9 entirely and is increasingly used in research settings 7
• The correlation between PHQ-8 and PHQ-9 total scores is 0.996, indicating near-perfect equivalence 7
• At the standard cutoff of 10, the PHQ-8 is minimally less sensitive (by 0.02-0.05) but maintains similar specificity 7
• However, using the PHQ-8 means you lose the opportunity to screen for self-harm thoughts, which is a significant clinical disadvantage 7