Master Psychiatry
for DHA

What the DHA Tests in Psychiatry

The DHA Psychiatry exam tests the ability to recognise and manage common psychiatric disorders in a primary care or emergency setting, with emphasis on differential diagnosis, risk assessment, and pharmacotherapy. Candidates must demonstrate knowledge of DSM-5 or ICD-10 diagnostic criteria for major depressive disorder, bipolar disorder, schizophrenia, generalised anxiety disorder, panic disorder, obsessive-compulsive disorder, and substance use disorders. Exam questions often present clinical vignettes requiring selection of first-line medications (e.g., SSRIs, antipsychotics, mood stabilisers), identification of side effects (e.g., extrapyramidal symptoms, serotonin syndrome), and application of crisis management protocols (e.g., for acute agitation, suicide risk). Understanding of the Mental Health Act principles, capacity assessment, and referral thresholds to psychiatry is also tested. Specific cut-off values such as the Hamilton Depression Rating Scale score for severity or the CAGE questionnaire for alcohol misuse may appear.

High-Yield Concepts

• Major Depressive Disorder – Diagnosis and First-Line Treatment: ICD-10 requires at least 2 core symptoms (depressed mood, anhedonia, reduced energy) plus 2-4 other symptoms for at least 2 weeks. First-line pharmacotherapy is an SSRI (e.g., sertraline 50-200 mg/day, escitalopram 10-20 mg/day). For severe depression with psychosis, consider augmentation with olanzapine or ECT.
• Bipolar Disorder – Acute Mania Management: First-line for acute mania: lithium (target serum 0.6-1.2 mmol/L), valproate (500-2000 mg/day, monitor levels), or olanzapine (10-20 mg/day). Avoid antidepressants in acute mania. For rapid cycling, consider lamotrigine or valproate over lithium.
• Schizophrenia – Antipsychotic Choice and Side Effects: First-line: second-generation antipsychotics (e.g., risperidone 2-6 mg/day, olanzapine 5-20 mg/day). Monitor for extrapyramidal symptoms (use AIMS scale), metabolic syndrome (weight, lipids, glucose), and QT prolongation (ECG). Clozapine is reserved for treatment-resistant cases (neutrophil count monitoring mandatory).
• Generalised Anxiety Disorder – Pharmacotherapy and CBT: First-line: SSRI (e.g., sertraline 50-200 mg/day) or SNRI (e.g., venlafaxine 75-225 mg/day). Pregabalin (150-600 mg/day) is an alternative. Avoid benzodiazepines beyond short-term use (max 2-4 weeks) due to dependence risk. Cognitive behavioural therapy is first-line non-pharmacological.
• Panic Disorder – Diagnosis and Acute Attack Management: ICD-10 requires recurrent unexpected panic attacks (palpitations, chest pain, dizziness, fear of dying) with avoidance behaviour. First-line: SSRI (e.g., citalopram 20-40 mg/day) or SNRI. For acute attack, use lorazepam 1-2 mg sublingual or IM, but not as maintenance.
• Obsessive-Compulsive Disorder – Treatment Algorithm: First-line: high-dose SSRI (e.g., fluoxetine 20-80 mg/day, sertraline 50-200 mg/day) plus exposure and response prevention therapy. If inadequate response, augment with clomipramine (10-250 mg/day, monitor ECG) or antipsychotic (e.g., aripiprazole 5-15 mg/day).
• Alcohol Withdrawal – CIWA-Ar Protocol and Detoxification: Assess severity using CIWA-Ar score (≥10 indicates need for pharmacotherapy). First-line: chlordiazepoxide (20-100 mg 4-6 hourly as needed) or diazepam (10-20 mg PRN). Give thiamine 100 mg IV/IM for 3-5 days to prevent Wernicke encephalopathy. Monitor for seizures and delirium tremens.
• Suicide Risk Assessment – Key Factors and Immediate Steps: Assess using SAFE-T: ask about suicidal ideation, plan, intent, means, and protective factors. High risk: immediate psychiatric referral, remove means, consider involuntary admission under Mental Health Act. Use Columbia-Suicide Severity Rating Scale (C-SSRS) to quantify risk.

Common Traps in Psychiatry Questions

• Candidates often prescribe benzodiazepines as first-line for GAD or panic disorder, but guidelines recommend SSRIs/SNRIs first.
• In bipolar depression, giving an antidepressant without a mood stabiliser can precipitate a manic switch.
• Confusing extrapyramidal symptoms (dystonia, akathisia) with psychiatric worsening, leading to inappropriate antipsychotic dose increase.
• For alcohol withdrawal, using short-acting benzodiazepines (e.g., lorazepam) instead of long-acting (e.g., chlordiazepoxide) increases seizure and delirium risk.
• Assuming a patient with schizophrenia and negative symptoms (e.g., apathy) is depressed, and starting an SSRI without reviewing antipsychotic dose.
• In OCD, starting with too low an SSRI dose or not waiting 8-12 weeks for response, leading to premature treatment switching.

How to Revise Psychiatry for the DHA

Prioritise high-yield conditions: depression, bipolar mania, schizophrenia, anxiety disorders, and substance withdrawal. Questions are often scenario-based with a twist: e.g., a patient on SSRI develops agitation and hyperthermia (serotonin syndrome) or a patient with mania refuses medication (capacity and Mental Health Act). Practise differentiating between similar presentations (e.g., panic attack vs. myocardial infarction, hypomania vs. ADHD). Know first-line drugs by class, their side effect profiles, and monitoring requirements (e.g., lithium levels, clozapine WCC). For risk assessment, memorise the CAGE questionnaire (cut-off ≥2) and CIWA-Ar thresholds. Focus on British/international guidelines (e.g., NICE, BAP) rather than US-specific ones. Do not neglect child and adolescent psychiatry (e.g., ADHD treatment, conduct disorder) and liaison psychiatry (delirium vs. dementia).

Practise it: MedLumen has 60 Psychiatry questions for the DHA, each with a full explanation and references.