Generalised Anxiety Disorder

Generalised anxiety disorder (GAD) is persistent, excessive, and difficult-to-control worry about a number of everyday circumstances, rather than anxiety confined to a specific trigger. It affects up to 6% of the Australian population and commonly overlaps with other anxiety disorders and with depression.

Diagnosis

Six months or more of excessive, hard-to-control worry, plus three or more of:

• Feeling restless, “keyed up,” or on edge
• Easily fatigued
• Difficulty concentrating, or “mind going blank”
• Irritability
• Muscle tension
• Sleep disturbance

Other common features: exaggerated startle response, impatience, sensitivity to noise, and — on the physical side — motor tension (headache, myalgia, trembling, restlessness) and autonomic overactivity (dry mouth, palpitations, sweating, flushing, a “lump in the throat,” diarrhoea/abdominal distress, urinary frequency, breathlessness, dizziness).

Diagnosis is made on history, after:

• excluding an organic cause simulating anxiety (examination + appropriate investigations), and
• excluding another psychiatric disorder — anxiety and major depression frequently co-exist, so actively screen for both.

Differentials (the “seven masquerades” list applies here): depression; alcohol or drug (including benzodiazepine) intoxication/withdrawal; hyperthyroidism; angina or arrhythmia; an iatrogenic drug effect; caffeine intoxication.

Management

Psychological therapy is first-line — CBT (identifying, challenging, and modifying maladaptive thoughts/feelings/behaviours) has the best evidence, and both low- and high-intensity exercise reduce anxiety symptoms. Alongside this:

• Explain the cause of symptoms and reassure the patient there’s no organic disease (only once that’s actually been established) — patients often “worry about worrying” (fear the anxiety itself is dangerous, or that they’re “going crazy”).
• Advise avoiding aggravating substances (caffeine, nicotine, other drugs).
• Arrange stress-management, relaxation, and mindfulness strategies, and regular exercise — don’t just leave this to the patient to organise alone.
• Provide ongoing supportive psychotherapy and practical coping-skills advice.

Pharmacotherapy

Medication is not a substitute for psychological/lifestyle therapy — those have the more durable benefit, so don’t rush to prescribe, and keep reassessing whether it’s still needed.

• SSRIs are first-line (escitalopram has the largest evidence base). SNRIs (duloxetine, venlafaxine) also have some evidence but are less durable than psychological approaches.
• Assess response at 2–4 weeks initially; full benefit may take 4–6 weeks or longer. If there’s an inadequate response after an effective dose for at least 4 weeks, consider a sequential trial of a second SSRI/SNRI before escalating further. If there’s a good response, continue at the same dose for at least 1 year before considering deprescribing.
• Stopping an SSRI commonly causes withdrawal symptoms — don’t mistake these for a relapse of the underlying anxiety.
• Propranolol helps social-anxiety-type anticipatory symptoms (e.g. before public speaking) — see Social Anxiety Disorder.
• Benzodiazepines have a limited role: reserve for patients who haven’t responded to at least two other therapies (e.g. psychological therapy + an antidepressant), use only short-term (stop within 6 weeks), and note they’re also useful for specific phobias (e.g. fear of flying, MRI claustrophobia).
• Buspirone is an alternative with negligible dependence potential — response can take 2–4 weeks (sometimes apparent by 7–10 days).

Typical SSRI/SNRI dosing:

Drug	Initial dose	Maximum dose
Citalopram	10 mg	40 mg
Escitalopram	5 mg	20 mg
Fluoxetine	10 mg	80 mg
Fluvoxamine	50 mg	300 mg (split dose above 150 mg)
Paroxetine	10 mg	60 mg
Sertraline	25 mg	200 mg
Duloxetine	30 mg	120 mg
Venlafaxine (controlled-release)	75 mg	225 mg

TCAs (e.g. imipramine 25 mg at night, titrating to 75 mg) are effective but not first-line given their adverse-effect burden, and are dangerous in overdose — use cautiously if there’s coexisting depression or self-harm risk.

If treatment-resistant (inadequate response to sequential SSRI/SNRI trials), options include combining psychosocial therapy with pharmacotherapy, referral to psychiatry, or adding pregabalin, quetiapine, or a benzodiazepine, or trialling mirtazapine/agomelatine:

• Pregabalin is rapidly effective (response often within a week; an early 20–30% improvement at 2 weeks predicts a good longer-term response). It is not TGA-approved for GAD in Australia — this remains off-label use. Typical regimen: 25 mg twice daily, increasing by 100 mg/day each week as tolerated to a maximum of 450 mg/day; continue at least a year before deprescribing (taper ~25–30% every 2 weeks to avoid precipitating a seizure). Carries a warning for altered/worsening mood and emergent suicidality, particularly in young people.
• Quetiapine reduces GAD symptoms but carries cardiometabolic/overdose/misuse risk and needs baseline and ongoing monitoring.

Separation anxiety disorder

A related but distinct DSM-5 diagnosis, usually of childhood onset (though it can persist into or arise in adulthood): developmentally inappropriate, excessive fear/anxiety about separation from attachment figures (persisting ≥4 weeks in children/adolescents, ≥6 months in adults) — school refusal, reluctance to sleep away from home, nightmares about separation, physical symptoms when separation is anticipated. Psychosocial interventions (CBT, often family-involved for children) are first-line; pharmacotherapy (SSRIs) is reserved for significant or persisting symptoms, usually alongside psychological treatment.