The GAD-7 assesses seven core anxiety symptoms over the previous two weeks: 1) Feeling nervous, anxious, or on edge; 2) Not being able to stop or control worrying; 3) Worrying too much about different things; 4) Trouble relaxing; 5) Being so restless that it's hard to sit still; 6) Becoming easily annoyed or irritable; 7) Feeling afraid as if something awful might happen. Each item is rated on frequency from 0 (not at all) to 3 (nearly every day). The total score ranges from 0-21, with higher scores indicating greater anxiety severity. The tool also includes an optional functional impairment question assessing how anxiety symptoms affect daily life in work, home management, and relationships.

The GAD-7 demonstrates strong diagnostic accuracy: at the cutoff score of 10, sensitivity is 89% and specificity 82% for Generalized Anxiety Disorder. For any anxiety disorder (including panic, social anxiety, PTSD), sensitivity is 74% and specificity 81%. The area under the ROC curve is 0.92 for GAD and 0.84 for any anxiety disorder, indicating excellent diagnostic discrimination. A score of 8-9 suggests possible anxiety disorder warranting further assessment, while ≥10 indicates probable GAD requiring clinical evaluation. The GAD-7 also effectively tracks symptom severity, with a 4-point reduction representing clinically meaningful improvement. However, it's a screening tool, not a diagnostic instrument—formal diagnosis requires comprehensive clinical assessment considering symptom duration, impairment, and exclusion of other conditions.

GAD-7 scores are interpreted as: 0-4 = Minimal anxiety (normal range), 5-9 = Mild anxiety (monitoring recommended), 10-14 = Moderate anxiety (treatment consideration), 15-21 = Severe anxiety (immediate treatment recommended). However, clinical interpretation is nuanced: Scores 5-9 may represent subthreshold anxiety requiring watchful waiting or low-intensity interventions. Scores 10+ suggest probable Generalized Anxiety Disorder needing professional evaluation. The functional impairment question is crucial—even mild symptoms causing significant life disruption may warrant intervention. Specific symptom patterns (e.g., predominant physical vs. cognitive symptoms) also guide treatment approaches. Scores should be considered alongside duration (GAD requires ≥6 months of symptoms) and ruling out medical causes.

The GAD-7 specifically measures pathological anxiety distinguishable from normal worry by several features: 1) Intensity: Excessive worry disproportionate to actual risk; 2) Controllability: Inability to stop or control worrying (item 2 is particularly discriminative); 3) Pervasiveness: Worry about multiple domains (item 3); 4) Physical Symptoms: Restlessness, muscle tension, irritability (items 5-6); 5) Duration: Symptoms persisting most days for ≥6 months; 6) Impairment: Significant interference with functioning. Normal stress typically relates to specific stressors, diminishes when stressor resolves, and doesn't include the physical symptom cluster. The GAD-7's inclusion of both cognitive ("can't control worry") and physical ("restless," "irritable") symptoms helps differentiate clinical anxiety from transient stress.

While designed for Generalized Anxiety Disorder, the GAD-7 shows good screening performance for other anxiety disorders: sensitivity of 74% and specificity of 81% for any anxiety disorder (panic disorder, social anxiety, PTSD). Specific patterns may suggest different disorders: High scores on items 5 (restlessness) and 7 (fear of something awful) may indicate panic disorder. Social anxiety might show lower overall scores but specific fears. However, the GAD-7 cannot differentiate between anxiety disorders—it's a general anxiety screen. For specific disorders, additional tools are needed: Panic Disorder Severity Scale (PDSS) for panic, Social Phobia Inventory (SPIN) for social anxiety, PTSD Checklist (PCL-5) for trauma. The GAD-7 is often used alongside the PHQ-9 for depression screening, as anxiety and depression frequently co-occur.