What are the best screening tools for depression and anxiety?

Best Screening Tools for Depression and Anxiety

For depression screening, the PHQ-2/PHQ-9 two-step approach is recommended as the most effective screening tool, while for anxiety screening, the GAD-7 is the preferred instrument with optimal sensitivity and specificity.

Depression Screening Tools

Primary Recommendation: PHQ-2/PHQ-9 Two-Step Approach

• Step 1: Use the PHQ-2 (first two questions of PHQ-9) as initial screen
  • Questions: "Over the past 2 weeks, have you felt down, depressed, or hopeless?" and "Over the past 2 weeks, have you felt little interest or pleasure in doing things?"
  • Cutoff score: ≥2 indicates need for full PHQ-9 1
• Step 2: For positive PHQ-2 screens, administer full PHQ-9
  • Optimal cutoff: ≥8 for clinical populations 2
  • Traditional cutoff: ≥10 for general population 3

The PHQ-9 has demonstrated good sensitivity (83%) and specificity (61%) at a cutoff of ≥7 in diverse populations 2. It has strong psychometric properties with Cronbach's alpha of 0.86 4.

Alternative Depression Screening Options

• Two simple questions: Simply asking about mood and anhedonia may be as effective as longer instruments in primary care settings 1
• Center for Epidemiologic Study Depression Scale (CES-D): Good option but longer than PHQ-9
• Beck Depression Inventory: Well-validated but requires more time to complete

Anxiety Screening Tools

Primary Recommendation: GAD-7

• 7-item scale specifically designed for primary care settings 1
• Optimal cutoff: ≥8 for good balance of sensitivity and specificity 5
• Alternative cutoff: ≥10 for higher specificity but lower sensitivity 5
• Excellent internal consistency (Cronbach's alpha 0.91) 4

Alternative Anxiety Screening Options

• GAD-2: Ultra-brief 2-item version of GAD-7
  • Cutoff score: ≥3 3
  • Good for initial screening in time-limited settings
• Mini-SPIN: 3-item version of Social Phobia Inventory
  • Specifically for social anxiety disorder
  • Cutoff score: ≥6 (89% sensitivity, 90% specificity) 1

Implementation Considerations

Screening Algorithm

1. Initial Visit: Screen all patients using PHQ-2 and GAD-2
2. Positive Initial Screen: Administer full PHQ-9 and/or GAD-7
3. Regular Follow-up: Screen at appropriate intervals, especially with:
   • Changes in disease or treatment status
   • Transitions in care
   • Significant life events 1

Clinical Pearls

• Avoid relying solely on symptom count: Assessment should be phased and consider patient history and risk factors 1
• Pay attention to the self-harm item on PHQ-9: Consider risk assessment for patients endorsing thoughts of self-harm 1
• Consider cultural context: Sensitivity and specificity of these tools may vary across different populations 5, 6
• Ensure follow-up systems: Benefits from screening are unlikely without proper systems for diagnosis, treatment, and follow-up 1

Common Pitfalls

• Overreliance on screening tools: Positive screens should trigger full diagnostic interviews using standard diagnostic criteria 1
• Using inappropriate cutoffs: Optimal cutoffs may vary by population and setting 1
• Neglecting comorbidities: Depression and anxiety frequently co-occur and should both be assessed 3
• Failing to reassess: One-time screening is insufficient; regular reassessment is necessary, especially during transitions of care 1

Both the PHQ-9 and GAD-7 are brief, well-validated measures that can be completed in less than 5 minutes, making them practical for routine clinical use in busy primary care settings 3.