What are the best screening tests for depression and anxiety?

Best Screening Tests for Depression and Anxiety

For depression screening, the two-question approach asking about mood and anhedonia is as effective as longer instruments, while for anxiety screening, the Generalized Anxiety Disorder Scale (GAD-7) demonstrates the highest accuracy with moderate to high performance. 1

Depression Screening Tools

Primary Screening Options

• Two-question screening approach:

  • "Over the past 2 weeks, have you felt down, depressed, or hopeless?"
  • "Over the past 2 weeks, have you felt little interest or pleasure in doing things?"
  • This simple approach detects the majority of depressed patients and may perform better than longer instruments 1
  • Positive responses should trigger further assessment

• Patient Health Questionnaire (PHQ-9):

  • 9-item self-administered questionnaire
  • Good sensitivity (80-90%) and specificity (70-85%) 1, 2
  • Optimal cut-off score of 8-10 (≥8 recommended in cancer patients) 1, 2
  • Can be administered in less than 5 minutes
  • PHQ-2 (ultra-brief version) with cut-off ≥3 also effective 2

Other Validated Depression Screening Tools

• Beck Depression Inventory
• Zung Self-Depression Scale
• Center for Epidemiologic Study Depression Scale
• General Health Questionnaire
• Geriatric Depression Scale (specifically for older adults)

Anxiety Screening Tools

Primary Screening Option

• Generalized Anxiety Disorder Scale (GAD-7):
  • 7-item self-administered questionnaire
  • Demonstrates moderate to high accuracy (area under ROC curve 0.77-0.94) 1
  • Optimal cut-off score of ≥8-10 2, 3
  • GAD-2 (ultra-brief version) with cut-off ≥3 also effective 2

Special Populations

• Pregnant and postpartum women:

  • Edinburgh Postnatal Depression Scale can screen for both depression and anxiety
  • For anxiety screening specifically, performance is moderate (area under ROC curve 0.62-0.73) 1

• Adolescents:

  • Screen for Child Anxiety Related Emotional Disorders scale shows moderate performance 1

Implementation Algorithm

1. Initial screening:

   • Use the two-question approach for depression
   • Use GAD-7 for anxiety (or GAD-2 if time is limited)

2. For positive depression screens:

   • If either of the two initial questions is positive (score of 2, indicating symptoms more than half the days), administer the full PHQ-9 1
   • Pay special attention to the self-harm item on the PHQ-9 for risk assessment

3. For positive anxiety screens:

   • GAD-7 score ≥8 indicates probable anxiety disorder
   • Assess for comorbid conditions (panic disorder, PTSD, substance abuse)

4. Follow-up assessment:

   • All positive screening tests should trigger full diagnostic interviews using standard diagnostic criteria (DSM-5) 1
   • Assess severity, comorbidities, duration of symptoms, and functional impairment

Important Clinical Considerations

• Screening timing: Screen at initial visits, at appropriate intervals, and with changes in clinical status 1

• System requirements: Clinical practices that screen for depression and anxiety should have systems in place to ensure positive screens are followed by accurate diagnosis, effective treatment, and careful follow-up 1

• Cultural considerations: Optimal cut-off points may vary across different populations and settings 1

• False positives: About 24-40% of patients who screen positive for depression will have major depression; others may have subsyndromal conditions or comorbidities that still benefit from treatment 1

• Screening limitations: Screening tools have good sensitivity but only fair specificity; they are recommended as initial screening tools, but positive cases should be assessed using more comprehensive instruments 4, 5

• Comorbidity: Depression, anxiety, and somatization frequently co-occur; consider screening for all three conditions 2

By implementing these evidence-based screening approaches, clinicians can effectively identify patients with depression and anxiety, leading to appropriate treatment and improved outcomes.