How are the Generalized Anxiety Disorder 7-item scale (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) scored?

Scoring for the GAD-7 and PHQ-9

The GAD-7 and PHQ-9 are scored by assigning values of 0,1,2, and 3 to the response categories "not at all," "several days," "more than half the days," and "nearly every day," respectively, then summing the scores for all items. 1

GAD-7 Scoring and Interpretation

• The GAD-7 consists of 7 items, with total scores ranging from 0 to 21 1
• Severity levels are interpreted as:
  • 0-4: Minimal anxiety 1
  • 5-9: Mild anxiety 1
  • 10-14: Moderate anxiety 1
  • 15-21: Severe anxiety 1
• A cut-off score of ≥10 has good sensitivity and specificity for detecting generalized anxiety disorder, panic disorder, social anxiety disorder, and post-traumatic stress disorder 2
• Some research suggests a cut-off of ≥8 may provide better balance between sensitivity and specificity in certain populations 3
• The ultra-brief version (GAD-2) uses only the first two items with a recommended cut-off of ≥3 2

PHQ-9 Scoring and Interpretation

• The PHQ-9 consists of 9 items, with total scores ranging from 0 to 27 1
• While not explicitly stated in the evidence provided, the PHQ-9 is typically interpreted as:
  • 0-4: Minimal depression
  • 5-9: Mild depression
  • 10-14: Moderate depression
  • 15-19: Moderately severe depression
  • 20-27: Severe depression
• A cut-off score of ≥10 is generally recommended for detecting depressive disorders 2
• Recent research in some populations suggests a cut-off of ≥7 may provide optimal sensitivity and specificity 3
• Abbreviated versions include the PHQ-8 (omits the suicide item) and PHQ-2 (first two items only), with recommended cut-offs of ≥10 and ≥3 respectively 2

Clinical Application

• Both scales include a follow-up question about functional impairment: "If you checked off any problems, how difficult have these problems made it for you to do your work, take care of things at home, or get along with other people?" 1
• These scales should be used as screening tools, with positive results followed by further diagnostic assessment 1
• Regular reassessment using these scales helps track symptom changes and treatment response 4
• If moderate to severe symptoms are detected, patients should have further diagnostic assessment to confirm the presence of a mood or anxiety disorder 1

Important Considerations

• Both scales have demonstrated good reliability and validity across various populations 2, 5, 6
• The PHQ-9 and GAD-7 have been validated in multiple languages and settings 5, 6, 3
• While these scales are excellent for screening and monitoring, they should not replace clinical judgment for diagnosis 5
• Both scales may produce false positives, so positive screens should be followed by more comprehensive assessment 5