What scores on the Patient Health Questionnaire (PHQ)-2 warrant intervention?

PHQ-2 Scores That Warrant Intervention

A score of 3 or higher on the Patient Health Questionnaire-2 (PHQ-2) warrants further assessment and intervention for depression. 1, 2

Understanding the PHQ-2 Screening Tool

The PHQ-2 is a brief, two-question screening tool that assesses the frequency of depressed mood and anhedonia (loss of interest or pleasure) over the past two weeks. Each question is scored from 0 ("not at all") to 3 ("nearly every day"), with a total possible score ranging from 0 to 6.

The two questions assess:

1. Little interest or pleasure in doing things
2. Feeling down, depressed, or hopeless

Evidence-Based Scoring Thresholds

Research supports the following interpretation of PHQ-2 scores:

• Score ≥ 3: This is the standard cutoff with a sensitivity of 83% and specificity of 92% for major depression 2. This threshold is widely accepted as indicating the need for further assessment.

• Score of 2: Some evidence suggests that using a lower threshold of 2 may detect more cases of depression, though with lower specificity (78% compared to 92% with a cutoff of 3) 3.

Clinical Algorithm for PHQ-2 Screening

1. Administer the PHQ-2 during initial assessment or at regular intervals

2. Score interpretation:

   • Score 0-2: Low risk for major depression
   • Score ≥ 3: High risk for major depression that warrants further assessment

3. For scores ≥ 3:

   • Administer the full PHQ-9 to assess depression severity 1
   • Conduct a clinical interview to confirm diagnosis
   • Evaluate for suicidal ideation (particularly item 9 on the PHQ-9)
   • Assess for comorbid conditions

4. For scores of 2:

   • Consider clinical context and risk factors
   • Lower threshold may be appropriate in high-risk populations
   • Clinical judgment may warrant administering the PHQ-9 even with scores of 2

Special Considerations

• Cancer patients: The American Society of Clinical Oncology recommends that patients with a PHQ-2 score of 2 or 3 should receive further assessment with the full PHQ-9 1.

• Elderly patients: The PHQ-2 maintains good sensitivity in geriatric populations, with affirmative answers warranting administration of the full PHQ-9 1.

• Cultural considerations: Optimal cutoff scores may vary across different cultural and linguistic groups. For example, in Spanish-speaking populations, optimal cutoffs may range from ≥1 to ≥2 4.

Pitfalls and Caveats

• False negatives: Some patients with depression may score below the cutoff threshold. Clinical judgment should always supplement screening results.

• Accuracy limitations: The PHQ-2 is a screening tool, not a diagnostic instrument. Positive screens require confirmation through clinical assessment.

• Suicidality assessment: The PHQ-2 does not assess suicidal ideation, which is a critical component of the full PHQ-9 (item 9).

• Comorbid conditions: Medical conditions, substance use, and other psychiatric disorders may affect PHQ-2 scores and should be considered in interpretation.