Quick Overview
Generalised Anxiety Disorder (GAD) is persistent, excessive worry about multiple domains (≥6 months) causing significant functional impairment. Affects 4-5% of UK adults, twice as common in women. NICE CG113 emphasises stepped care starting with low-intensity interventions before pharmacotherapy, optimising resource allocation while maintaining clinical effectiveness.
Core Facts & Concepts
Diagnostic Criteria (ICD-10/DSM-5)
- Duration: Anxiety/worry present most days for ≥6 months
- Multiple domains: Worry across ≥2 life circumstances (work, health, finances, relationships)
- Uncontrollable: Patient finds worry difficult to control
- Physical symptoms (≥3 required): Restlessness, fatigue, concentration difficulty, irritability, muscle tension, sleep disturbance
GAD-7 Assessment Tool Interpretation
- Score 0-4: Minimal anxiety
- Score 5-9: Mild anxiety (consider low-intensity intervention)
- Score 10-14: Moderate anxiety (consider high-intensity intervention)
- Score 15-21: Severe anxiety (refer specialist services if needed)

Key Epidemiology & Risk Factors
- Peak onset: 35-54 years
- Comorbidity: 50-90% have coexisting depression
- Chronic course: 50% remain symptomatic at 5 years without treatment
- Risk factors: Female sex, chronic physical illness, substance misuse, childhood adversity
Stepped Care Model (NICE CG113)
| Step | Intervention | Provider |
|---|---|---|
| Step 1 | Identification, psychoeducation, active monitoring | Primary care |
| Step 2 | Low-intensity psychological intervention (guided self-help, psychoeducation groups) | IAPT/primary care |
| Step 3 | High-intensity intervention (CBT) OR drug treatment | Primary care ± mental health |
| Step 4 | Specialist assessment, complex drug/psychological treatment | Secondary care |
Problem-Solving Approach
Clinical Assessment Pathway
- Screen with GAD-7 in primary care (routine in patients presenting with anxiety symptoms)
- Assess functional impairment: Work, relationships, daily activities
- Rule out physical causes: Hyperthyroidism, cardiac arrhythmias, substance withdrawal, caffeine excess
- Evaluate comorbidities: Depression (PHQ-9), panic disorder, PTSD, substance misuse
- Risk assessment: Self-harm, suicide risk (especially with comorbid depression)

Pharmacotherapy Selection (NICE CG113)
First-line SSRI:
- Sertraline preferred (evidence base, cost-effectiveness)
- Alternative SSRIs: Escitalopram, paroxetine
- Start low dose, review at 2-4 weeks, therapeutic trial 12 weeks
- Warn: Increased anxiety first 2 weeks, discontinuation symptoms
Second-line SNRI:
- Venlafaxine XL or duloxetine if SSRI ineffective/not tolerated
- Venlafaxine requires monitoring: BP at baseline and dose increases (hypertension risk)
Avoid:
- Benzodiazepines (dependence risk, use only acute crisis <2-4 weeks)
- Antipsychotics as monotherapy
⚠️ Warning: SSRI/SNRI may worsen anxiety initially. Advise patients to continue for 2 weeks before judging efficacy. Review suicidal ideation in first month, especially age <30 years.
Analysis Framework
Differential Diagnosis of Persistent Anxiety
| Condition | Discriminating Features |
|---|---|
| GAD | Multiple worry domains, persistent ≥6 months, no specific trigger |
| Panic Disorder | Discrete panic attacks, anticipatory anxiety about attacks |
| Social Anxiety | Fear limited to social/performance situations |
| OCD | Intrusive thoughts + compulsive rituals |
| PTSD | Trauma history, flashbacks, avoidance, hypervigilance |
| Hyperthyroidism | Weight loss, tremor, heat intolerance, ↑TSH |
| Substance misuse | Caffeine >400mg/day, alcohol withdrawal, stimulant use |
Treatment Selection Criteria
Patient with GAD (GAD-7 ≥5)
↓
Mild-moderate (GAD-7: 5-14) + patient preference?
↓
YES → Step 2: Low-intensity psychological intervention
(Guided self-help, computerised CBT)
Duration: 6-8 weeks
↓
NO or inadequate response
↓
Step 3: Choice of high-intensity intervention
↓
Patient preference + availability?
↓
Prefers psychological → CBT (16-20 sessions)
Prefers medication → SSRI (sertraline first-line)
Severe (GAD-7: 15-21) → Consider both CBT + SSRI
↓
Review at 12 weeks
↓
Inadequate response?
↓
YES → Switch SSRI or trial SNRI + consider Step 4 referral
NO → Continue, review every 8-12 weeks
Visual Aid
SSRI vs SNRI Selection
| Factor | SSRI (Sertraline) | SNRI (Venlafaxine/Duloxetine) |
|---|---|---|
| Line | First-line | Second-line |
| Evidence | Strongest for GAD | Reserve for SSRI failure |
| Tolerability | Better (fewer discontinuation) | More side effects |
| Monitoring | None required | BP monitoring needed (venlafaxine) |
| Comorbidity | Depression, panic | Chronic pain (duloxetine advantage) |
| Cost | Lower | Higher |
Key Points Summary
✓ GAD-7 score ≥10 indicates need for treatment; score ≥15 suggests high-intensity intervention or specialist referral
✓ Stepped care mandatory: Start Step 2 low-intensity psychological (guided self-help) before pharmacotherapy unless severe or patient preference
✓ Sertraline first-line SSRI per NICE CG113; therapeutic trial requires 12 weeks at adequate dose before switching
✓ Venlafaxine/duloxetine (SNRIs) reserved for SSRI failure/intolerance; venlafaxine requires BP monitoring at baseline and dose increases
✓ Benzodiazepines avoided except acute crisis (<2-4 weeks); high dependence risk contradicts chronic GAD management
✓ CBT gold standard psychological therapy: 16-20 sessions, equivalent efficacy to medication, preferred by many patients
✓ Screen for comorbidities: 50-90% have depression (use PHQ-9); always assess suicide risk especially when initiating SSRI/SNRI age <30
📌 Remember: GAD requires 6+ months - shorter duration suggests adjustment disorder or acute stress reaction, altering management approach
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