SN6 SHORT NOTE 5M

Write a short note on anxiety disorders.

General Medicine · Final Professional

Definition

Anxiety is a normal adaptive response to threat. It becomes a disorder when it is excessive, persistent, out of proportion to any real danger, and impairs functioning. Anxiety disorders are the commonest psychiatric disorders, with a lifetime prevalence around 15–20%, and are twice as common in women.

Classification

Disorder	Key Features
Generalised anxiety disorder	Free-floating, persistent worry about multiple everyday matters for ≥ 6 months, with restlessness, fatigue, poor concentration, irritability, muscle tension and disturbed sleep
Panic disorder	Recurrent unexpected panic attacks — abrupt surges of intense fear peaking within 10 minutes, with palpitations, chest pain, dyspnoea, choking, sweating, trembling, fear of dying or going mad, depersonalisation — plus persistent worry about further attacks
Agoraphobia	Fear of situations where escape is difficult (crowds, public transport, open spaces), leading to avoidance; often follows panic disorder and may confine the patient to home
Social anxiety disorder	Fear of scrutiny and humiliation in social or performance situations, with blushing, tremor and avoidance
Specific phobia	Marked fear of a circumscribed object or situation — heights, animals, injections, blood (the last uniquely causing vasovagal syncope)
Post-traumatic stress disorder	Following a traumatic event: re-experiencing (flashbacks, nightmares), avoidance, hyperarousal, and negative alterations in mood and cognition, lasting > 1 month

Somatic Symptoms

Anxiety presents physically far more often than psychologically in general practice: palpitations, chest tightness, dyspnoea, dizziness, tremor, sweating, dry mouth, urinary frequency, diarrhoea, headache and globus sensation. Hyperventilation produces respiratory alkalosis with perioral and peripheral paraesthesia and carpopedal spasm, which frightens the patient further and sustains the attack.

Differential Diagnosis — Organic Mimics

Always exclude a physical cause before diagnosing an anxiety disorder:

Hyperthyroidism — the classic mimic; check TSH in every case.
Phaeochromocytoma — episodic headache, sweating, palpitations with hypertension.
Hypoglycaemia, arrhythmia (especially paroxysmal SVT), asthma, pulmonary embolism.
Substance-related: caffeine excess, stimulants, salbutamol, thyroxine; and withdrawal from alcohol or benzodiazepines.
Depression — anxiety is a prominent symptom of depression, and the two are frequently comorbid.

Management

Psychological (first-line):

Cognitive behavioural therapy — identifies and challenges catastrophic misinterpretation of bodily sensations, and is the treatment of choice for panic disorder.
Graded exposure for phobias and agoraphobia; applied tension rather than relaxation for blood-injury phobia.
Relaxation training, breathing control for hyperventilation, sleep hygiene, and reduction of caffeine, alcohol and nicotine.

Pharmacological:

SSRIs are first-line drug treatment for GAD, panic disorder, social anxiety and PTSD. Start at a low dose — anxious patients are sensitive to initial jitteriness — and titrate upwards.
SNRIs (venlafaxine, duloxetine) are effective alternatives.
Pregabalin for GAD; propranolol for the autonomic symptoms of performance anxiety.
Buspirone for GAD, without dependence risk.

DANGER / REMEMBER

Benzodiazepines should be used only short-term — no more than 2–4 weeks — for severe acute anxiety while an SSRI takes effect. Longer use causes tolerance, dependence and a withdrawal syndrome (rebound anxiety, insomnia, tremor, and seizures on abrupt cessation). Prescribing them as long-term treatment for chronic anxiety is a common and serious error.

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