😟 Anxiety disorders are among the most common mental health conditions. They include generalised anxiety disorder (GAD), phobias, and obsessive–compulsive disorder (OCD). These conditions cause significant distress and functional impairment but are often treatable with psychological and/or pharmacological interventions.

📖 About

• Anxiety: Excessive worry, often without a proportionate trigger.
• Phobias: Marked fear of a specific object/situation, leading to avoidance behaviour.
• OCD: Intrusive thoughts (obsessions) + repetitive behaviours (compulsions) aimed at reducing distress.

🔍 Epidemiology

• Lifetime prevalence: Anxiety disorders ~15–20%, phobias ~10%, OCD ~2–3%.
• Peak onset: teens–early adulthood.
• ♀️ More common in women, though OCD is equally distributed.
• Strong associations with depression and substance misuse.

🧠 Pathophysiology

• Dysregulation of serotonin, noradrenaline, and dopamine pathways.
• Overactive amygdala → exaggerated fear response.
• Genetic predisposition + environmental triggers (trauma, stress, learned behaviours).
• In OCD → dysfunction in orbitofrontal cortex–basal ganglia circuits.

📋 Clinical Features

• Generalised Anxiety Disorder (GAD): Excessive worry, restlessness, poor concentration, irritability, muscle tension, sleep disturbance.
• Phobias: Immediate anxiety on exposure, avoidance, physical symptoms (palpitations, sweating, trembling).
• OCD:
  • Obsessions: intrusive, distressing thoughts (contamination, harm, symmetry).
  • Compulsions: repetitive acts (washing, checking, counting) to reduce anxiety.

🛠️ Risk Factors

• Family history of anxiety or mood disorders.
• Adverse childhood experiences.
• Personality traits (perfectionism, high neuroticism).
• Substance misuse (alcohol, caffeine, drugs).
• Medical illness: thyroid disease, cardiac arrhythmias, asthma.

🔬 Investigations

Primarily a clinical diagnosis, but rule out secondary causes:

• Bloods: TFTs, glucose, FBC, U&E (exclude anaemia, thyroid disease, metabolic causes).
• Screen for depression, substance use.
• Psychological scales: GAD-7, PHQ-9, Yale-Brown Obsessive Compulsive Scale (Y-BOCS).

💊 Management Principles

• 🧑‍⚕️ Psychoeducation & Self-help: Reassurance, lifestyle advice (reduce caffeine, alcohol, improve sleep, exercise).
• 🧠 Psychological therapies: – CBT first-line for anxiety, phobias, and OCD. – Exposure therapy for phobias. – ERP (exposure and response prevention) for OCD.
• 💊 Pharmacological: – SSRIs (sertraline, fluoxetine, citalopram) first-line for anxiety, phobias, and OCD. – Consider SNRIs (venlafaxine) or pregabalin for resistant anxiety. – Avoid benzodiazepines except short-term crisis use (dependence risk).
• 👥 Multidisciplinary support: Primary care, psychiatry, IAPT services, occupational support.

🚨 Red Flags

• Active suicidal ideation or self-harm risk.
• Severe functional impairment (can’t leave house, can’t work).
• Failure of first-line therapies → needs specialist referral.
• Psychotic symptoms or unusual intrusive thoughts (e.g., command hallucinations).

📊 Differential Diagnoses

• Depression with anxiety symptoms.
• PTSD.
• Substance withdrawal (alcohol, benzodiazepines).
• Medical: hyperthyroidism, pheochromocytoma, cardiac arrhythmia.

📚 Exam Pearls

• OCD = obsessions (thoughts) + compulsions (acts) → must consume >1h/day or cause significant impairment.
• Phobias respond well to graded exposure therapy.
• SSRIs are the pharmacological backbone → but always combine with psychological therapy.
• Always exclude organic causes before labelling as primary anxiety disorder.