Generalised anxiety disorder (GAD)

Definition

Generalised anxiety disorder (GAD) is a chronic psychiatric condition characterised by excessive, uncontrollable worry about multiple aspects of life (e.g., work, health, finances, relationships) for most days over a period of at least six months, accompanied by physical and psychological symptoms.

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Epidemiology

• Lifetime prevalence: Approximately 5–6% in the general population

• Female-to-male ratio: About 2:1

• Onset is usually in late adolescence to early adulthood, but can occur at any age

• Frequently co-occurs with major depressive disorder, other anxiety disorders, and substance use disorders

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Etiology and Risk Factors

Biological factors:

• Dysregulation of neurotransmitters: serotonin, norepinephrine, gamma-aminobutyric acid (GABA)

• Overactivation of amygdala and limbic system

• Genetic predisposition (heritability ~30%)

Psychological factors:

• Cognitive distortions (catastrophising, overestimation of risk)

• Maladaptive coping mechanisms

• History of childhood adversity or trauma

Environmental factors:

• Chronic stressors (occupational, financial, interpersonal)

• Coexisting medical illnesses

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Diagnostic Criteria (DSM-5)

A. Excessive anxiety and worry, occurring more days than not for at least 6 months, about multiple events or activities
B. Difficulty controlling the worry
C. Anxiety/worry associated with ≥3 of the following (≥1 in children):

• Restlessness or feeling keyed up/on edge

• Being easily fatigued

• Difficulty concentrating or mind going blank

• Irritability

• Muscle tension

• Sleep disturbance (difficulty falling/staying asleep, restless sleep)

D. Symptoms cause clinically significant distress or impairment
E. Not due to substances, medical condition, or other mental disorder

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Clinical Features

Psychological symptoms:

• Persistent worry disproportionate to actual threat

• Feeling tense, keyed up, or on edge

• Anticipatory anxiety

• Difficulty relaxing

Physical symptoms:

• Muscle tension, headaches

• Trembling, twitching

• Sweating, nausea, diarrhoea

• Palpitations, dizziness

• Sleep disturbances

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Differential Diagnosis

• Panic disorder

• Social anxiety disorder

• Obsessive–compulsive disorder

• Post-traumatic stress disorder

• Major depressive disorder

• Hyperthyroidism, pheochromocytoma, arrhythmias

• Substance-induced anxiety

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Assessment

• Clinical interview – symptom onset, duration, triggers, functional impairment

• Screening tools:

  • GAD-7 (Generalised Anxiety Disorder 7-item scale)

  • Hamilton Anxiety Rating Scale (HAM-A)

• Evaluate for comorbid psychiatric or medical conditions

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Management

Treatment is multimodal, incorporating psychotherapy, pharmacotherapy, and lifestyle interventions.

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1. Psychotherapy

First-line: Cognitive Behavioural Therapy (CBT)

• Addresses maladaptive thought patterns

• Includes cognitive restructuring, worry exposure, relaxation training

• Duration: typically 12–20 sessions

Other modalities:

• Mindfulness-based stress reduction (MBSR)

• Acceptance and commitment therapy (ACT)

• Psychodynamic therapy (less evidence-based for GAD)

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2. Pharmacological Treatment

First-line pharmacotherapy: Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin–Norepinephrine Reuptake Inhibitors (SNRIs)

SSRIs:

• Escitalopram: 10 mg orally once daily, may increase to 20 mg/day after 1–2 weeks

• Paroxetine: 20 mg orally once daily, may increase to 50 mg/day

• Sertraline: 25–50 mg orally once daily, titrate up to 200 mg/day

SNRIs:

• Venlafaxine XR: 37.5–75 mg orally once daily, increase to 150–225 mg/day

• Duloxetine: 30 mg orally once daily, increase to 60–120 mg/day

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Second-line agents:

• Buspirone: 7.5 mg orally twice daily, increase by 5 mg every 2–3 days to 20–30 mg/day (max 60 mg/day)

• Pregabalin: 150 mg/day in 2–3 divided doses, may increase to 300–600 mg/day (not approved in all countries)

• Hydroxyzine: 25–50 mg orally three to four times daily (short-term use)

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Adjunctive/short-term options:

• Benzodiazepines:

  • Diazepam: 2–10 mg orally two to four times daily

  • Lorazepam: 1–3 mg orally in divided doses

  • Use short-term (2–4 weeks) for acute relief due to risk of dependence and withdrawal

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3. Lifestyle and Supportive Measures

• Regular aerobic exercise (≥150 min/week)

• Adequate sleep hygiene

• Reduction of caffeine, nicotine, and alcohol

• Stress management techniques: meditation, yoga, breathing exercises

• Support groups and psychoeducation

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Special Populations

• Pregnancy: Prefer psychotherapy; if medication needed, use SSRIs with better safety data (e.g., sertraline)

• Elderly: Start low, go slow with medications due to sensitivity and drug interactions

• Comorbid depression: SSRIs/SNRIs treat both conditions effectively

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Prognosis

• Chronic course with waxing and waning symptoms

• Early intervention improves long-term outcomes

• Many patients require long-term management to prevent relapse