Makindo Medical Notes

Related Subjects: |Psychiatric Emergencies |Depression |Mania |Schizophrenia |Suicide |Acute Psychosis |Delusions |General Anxiety Disorder |Obsessive-Compulsive disorder |Wernicke Korsakoff Syndrome |Medically Unexplained symptoms |Postpartum/Postnatal Depression |Postpartum / Postnatal Psychosis |Eating disorders in Children

🧠 About

• Obsessive-Compulsive Disorder (OCD) is characterised by recurrent, intrusive, unwanted, stereotyped, distressing, and irrational thoughts (obsessions) and repetitive behaviours or rituals (compulsions).
• Peak onset: typically 20–40 years.
• Patients usually have insight (they know the thoughts are their own, unlike psychotic disorders).

🤝 Associations

• Neurological: Sydenham’s chorea, Huntington’s disease, Parkinson’s disease.
• Psychiatric: Depression, anxiety, Tourette’s syndrome (tic disorders).

🧬 Aetiology

• Structural changes: reduced volume of the caudate nucleus.
• Hyperactivity in the orbitofrontal cortex and caudate (PET scans show increased metabolic activity).
• Likely interplay of genetics, serotonin dysfunction, and environmental stressors.

🔎 Clinical Features

• Obsessions: intrusive ruminations, doubts, or fears (e.g. contamination, harm).
• Compulsions: ritualistic behaviours (e.g. repeated checking, washing) performed to reduce anxiety.
• Symptoms are distressing, time-consuming, and interfere with daily life.
• Resisting compulsions worsens anxiety → vicious cycle.

💊 Management

• 📌 Patients often present late due to entrenched patterns of behaviour.
• First-line (NICE): Cognitive Behavioural Therapy (CBT) with exposure and response prevention (ERP).
• Medication: High-dose SSRIs (e.g. fluoxetine, sertraline) for at least 12 weeks before assessing response.
• Severe or resistant cases: Consider clomipramine (TCA) or augmentation strategies (antipsychotic add-on).
• Long-term management often requires a combination of therapy and medication.

📌 Key Exam Point

• Unlike psychosis, patients with OCD recognise obsessions as their own thoughts (i.e. egodystonic).

Cases — Obsessive–Compulsive Disorder (OCD)

• Case 1 — Contamination fear 🧼: A 25-year-old woman reports intrusive thoughts that her hands are contaminated after touching doorknobs. She washes her hands 40–50 times per day, leading to cracked skin. She recognises the behaviour is excessive but feels compelled to continue. Diagnosis: OCD with contamination obsessions and cleaning compulsions. Managed with CBT (exposure–response prevention) and an SSRI.
• Case 2 — Checking behaviour 🔑: A 32-year-old man spends hours each night repeatedly checking that his front door is locked and the gas hob is switched off. Attempts to resist cause overwhelming anxiety. He is often late for work. Diagnosis: OCD with checking compulsions. Managed with CBT and escalation to clomipramine when SSRI trial is inadequate.
• Case 3 — Pure obsessional (“Pure O”) 💭: A 28-year-old teacher has recurrent intrusive thoughts of harming her baby, which she finds distressing and abhorrent. She has no history of violence and avoids being alone with the infant. Diagnosis: OCD with intrusive harm obsessions without overt compulsions. Managed with CBT and SSRI therapy, with reassurance these thoughts do not reflect intent.

Teaching Point 🩺: OCD is characterised by obsessions (intrusive, distressing thoughts) and/or compulsions (repetitive behaviours or mental acts to relieve anxiety). Insight is usually preserved. First-line treatment = CBT with exposure–response prevention ± SSRIs. Clomipramine is second line.