How do I interpret and manage Patient Health Questionnaire‑9 (PHQ‑9) and Generalized Anxiety Disorder‑7 (GAD‑7) scores?

Interpreting and Managing PHQ-9 and GAD-7 Scores

Use standardized cutoff scores to stratify symptom severity and trigger specific clinical actions: for PHQ-9, scores of 1-7 indicate minimal symptoms requiring no intervention, 8-14 indicate moderate symptoms warranting consultation, and 15-27 indicate severe symptoms requiring immediate psychiatric referral; for GAD-7, scores of 0-4 indicate minimal anxiety, 5-9 mild anxiety, 10-14 moderate anxiety, and 15-21 severe anxiety requiring specialist evaluation 1.

PHQ-9 Score Interpretation and Management Algorithm

Scoring System

The PHQ-9 assesses depressive symptoms over the past two weeks, with each of 9 items scored 0-3 (not at all, several days, more than half the days, nearly every day), yielding a total score of 0-27 1.

Severity Categories and Actions

Minimal Symptoms (Score 1-7)

• No or minimal depressive symptoms present
• Patient demonstrates effective coping skills and social support
• Action: No further screening needed; routine follow-up 1

Moderate Symptoms (Score 8-14)

• Subthreshold to moderate depressive symptoms
• Functional impairment ranges from mild to moderate
• Action: Seek consultation with psychology or psychiatry for diagnostic determination 1
• Consider medical causes (medication side effects, thyroid disorders, other medical conditions) 1, 2
• Initiate treatment for underlying medical contributors (unrelieved pain, fatigue) 1

Moderate-to-Severe/Severe Symptoms (Score 15-27)

• Most depressive symptoms present
• Symptoms interfere moderately to markedly with functioning
• Action: Immediate referral to psychology and/or psychiatry for formal diagnosis and treatment 1
• Conduct comprehensive diagnostic assessment to identify nature and extent of symptoms and presence of mood disorder 1

Critical Safety Assessment

Before any scoring interpretation, immediately assess for risk of self-harm or harm to others 1. If present:

• Emergency referral to licensed mental health professional
• Facilitate safe environment with one-to-one observation
• Initiate harm-reduction interventions immediately 1

The presence of severe agitation, psychosis, or confusion (delirium) also warrants emergency evaluation regardless of PHQ-9 score 1.

Efficient Two-Step Screening Approach

For time-constrained settings, use the PHQ-2 (first two questions: anhedonia and depressed mood) 1:

• If score is 0-1: No further screening needed
• If score is 2-3: Complete remaining 7 items of PHQ-9 1

This approach reduces screening burden, as only 25-30% of patients require the full questionnaire 1.

GAD-7 Score Interpretation and Management Algorithm

Scoring System

The GAD-7 assesses anxiety symptoms over the past two weeks, with 7 items scored 0-3 (not at all, several days, more than half the days, nearly every day), yielding a total score of 0-21 1.

Severity Categories and Actions

Minimal Anxiety (Score 0-4)

• None or mild anxiety symptoms
• No or minimal functional impairment
• Effective coping skills and social support present
• Action: No intervention needed; routine monitoring 1

Mild Anxiety (Score 5-9)

• Mild anxiety symptoms present
• May present as worries or concerns about cancer (if applicable) but also multiple other areas
• Fatigue, sleep disturbances, irritability, and concentration difficulties may be present
• Functional impairment ranges from mild to moderate
• Action: Consider possible comorbid anxiety diagnoses (panic disorder, social phobia) 1
• Provide supportive care and monitor

Moderate Anxiety (Score 10-14)

• Moderate anxiety symptoms
• Symptoms interfere moderately with functioning
• Action: Seek consultation with psychology or psychiatry 1
• Evaluate for comorbid conditions
• Consider medical causes (substance use, chronic illness) 1

Severe Anxiety (Score 15-21)

• Severe anxiety symptoms
• Symptoms interfere markedly with functioning
• Symptoms not responding to initial interventions
• Action: Immediate referral to psychology and/or psychiatry for diagnosis and treatment 1

Alternative Ultra-Brief Screening: GAD-2

For rapid screening, use the first two GAD-7 items 3, 4:

• Cutoff ≥3 has sensitivity 89% and specificity 90% for detecting anxiety disorders
• Positive screen requires completion of full GAD-7 3

Key Clinical Considerations

Timing of Screening

Screen at these critical timepoints 1:

• Initial diagnosis/start of treatment
• Regular intervals during treatment
• 3,6, and 12 months post-treatment
• At disease recurrence or progression
• During transitions to palliative/end-of-life care
• During personal crises or family transitions

Important Caveats

Somatic Symptom Overlap: Both scales include somatic symptoms that may overlap with medical conditions 5. The PHQ-9 and GAD-7 have two-factor structures (cognitive-affective and somatic domains). Consider reviewing subscale scores, not just totals, particularly in medically ill populations 5.

Specificity Limitations: While these scales have good sensitivity, specificity for specific psychiatric diagnoses is limited 6. A positive screen indicates increased risk requiring further comprehensive assessment, not a definitive diagnosis 6.

Cutoff Variations: The recommended PHQ-9 cutoff of 8 (rather than the traditional 10) improves sensitivity in cancer populations 1. For GAD-7, a cutoff of 9 provides better positive likelihood ratio than 8 3.

Medical Causes: Always evaluate for substance-induced or medical causes of symptoms (medications like interferon, thyroid disorders, chronic pain, fibromyalgia) before attributing symptoms solely to psychiatric disorders 1, 2.

Comorbidity: Depression and anxiety frequently co-occur. Screen for both conditions, as GAD is commonly comorbid with mood disorders 1.

Treatment Considerations

When moderate-to-severe symptoms are identified, treatment should include 1:

• Pharmacologic interventions (antidepressants, anxiolytics)
• Non-pharmacologic interventions (psychotherapy, cognitive-behavioral therapy, psychoeducation, exercise)
• Delivered by appropriately trained professionals

First address medical contributors (unrelieved pain, fatigue, delirium) before or concurrent with psychiatric treatment 1.