Mental Health GP Exam Australia: Clinical Revision Guide

Mental health presentations constitute a massive proportion of daily general practice consultations in Australia. Consequently, the RACGP Applied Knowledge Test (AKT) and Key Feature Problem (KFP) exams consistently allocate a significant weighting of questions to this domain. You must expect questions targeting the diagnosis and management of major depressive disorder, generalised anxiety disorder, bipolar affective disorder, schizophrenia, substance use disorders, and acute suicide risk assessments.

Many candidates lose marks in mental health questions because they fail to document structured clinical assessments, select appropriate antidepressant titration schedules, or correctly outline the mandatory monitoring requirements for high-risk psychiatric medications like lithium or clozapine.

This clinical revision guide details the high-yield mental health topics you must master for the RACGP exams, maps them to current Australian guidelines, and highlights the common examiner-reported errors you must avoid to pass.

Depression Screening and Diagnosis: Diagnostic Standards

When managing depression, questions in the AKT test your ability to apply diagnostic criteria systematically and utilize validated screening tools correctly.

Validated Screening Tools

In Australian general practice, the following validated questionnaires are utilized to assist in screening, diagnosing, and monitoring response to treatment:

• Patient Health Questionnaire-9 (PHQ-9): A 9-item tool that aligns directly with DSM-5 diagnostic criteria for major depressive disorder. It is highly useful for measuring severity and tracking response to pharmacological or psychological therapy over time.
• Kessler Psychological Distress Scale (K10): A 10-item questionnaire that measures non-specific psychological distress in the past 4 weeks, heavily utilized in GP Mental Health Treatment Plans (MHTPs) to qualify patients for Medicare-subsidized psychology sessions.

Stepwise Pharmacological Management

For moderate-to-severe depression, first-line pharmacological treatment consists of Selective Serotonin Reuptake Inhibitors (SSRIs) due to their favourable safety profile and ease of titration:

• Medication Selection: Sertraline, escitalopram, and fluoxetine are standard first-line options. Sertraline is the preferred first-line agent in patients with a history of recent cardiovascular events (myocardial infarction or unstable angina) due to extensive safety data showing it does not adversely affect cardiac conduction or platelet aggregation.
• Titration Rules: Start at a standard starting dose (e.g. sertraline 50mg daily or escitalopram 10mg daily). Advise the patient that therapeutic response is delayed, typically taking 2-4 weeks to begin, and a full clinical trial requires 4-6 weeks at an adequate dose (or up to 8 weeks in older adults). Review the patient within 1-2 weeks of initiation to screen for increased anxiety or suicidal ideation.
• Adverse Effects: Common side effects include nausea, headache, sexual dysfunction (delayed ejaculation, anorgasmia), and hyponatremia (secondary to SIADH, particularly in older adults).

Antidepressant Complications: Serotonin Syndrome vs Discontinuation

Questions regarding the complications of antidepressant therapy are high-yield on the AKT, testing your ability to recognize medical emergencies and manage medication withdrawal safely.

Serotonin Syndrome

This is a life-threatening emergency caused by excessive serotonergic activity in the central nervous system, typically triggered by drug-to-drug interactions (e.g. combining an SSRI with another serotonergic drug like tramadol, MAOIs, linezolid, pethidine, or St John's wort). You must recognize the classic clinical triad:

1. Neuromuscular Excitation: Clonus (spontaneous, inducible, or ocular), hyperreflexia (particularly in the lower limbs), tremor, and muscular rigidity.
2. Autonomic Excitation: Hyperthermia (can exceed 40°C in severe cases), diaphoresis, tachycardia, hypertension, and pupil dilation (mydriasis).
3. Altered Mental Status: Agitation, confusion, anxiety, and delirium.

Management: Cease all serotonergic agents immediately. Provide supportive care including intravenous fluids, oxygen, and cooling measures. Administer benzodiazepines (e.g. diazepam) to manage muscle rigidity, agitation, and autonomic instability. Severe cases require emergency transfer to the intensive care unit.

Antidepressant Discontinuation Syndrome

Abrupt cessation of antidepressants, particularly those with a short half-life (e.g. venlafaxine, paroxetine), can precipitate discontinuation syndrome. Symptoms typically appear within 2-4 days of stopping the medication and include:

• Sensory disturbances: Classic "electric shock" sensations (brain zaps), paresthesias.
• Neurological: Dizziness, vertigo, headache.
• Psychological: Vivid dreams, anxiety, irritability, agitation.
• Somatic: Influenza-like symptoms (chills, sweating, myalgia), nausea, lethargy.

Prevention: Antidepressants should be gradually tapered over at least 4 weeks to avoid withdrawal symptoms. If discontinuation syndrome occurs, reassure the patient, restart the antidepressant at the last effective dose, and taper more slowly. Fluoxetine has a very long half-life and carries the lowest risk of discontinuation syndrome.

Bipolar Affective Disorder and Lithium Monitoring

Bipolar disorder questions test your ability to perform diagnostic screening and coordinate the strict monitoring protocols required for long-term mood stabilizer therapy.

Screening and Diagnosis

Screening is performed using the Mood Disorder Questionnaire (MDQ). A common error on the AKT is misdiagnosing bipolar disorder as unipolar depression and prescribing antidepressant monotherapy, which can precipitate a manic switch or rapid cycling. Always screen for a history of hypomanic or manic episodes before initiating antidepressants.

Lithium: The Gold Standard Mood Stabilizer

Lithium remains the first-line mood stabilizer for the long-term maintenance of bipolar disorder. However, it has an extremely narrow therapeutic index and requires strict monitoring:

• Therapeutic Levels: The target maintenance serum lithium level is 0.6 to 0.8 mmol/L. For acute manic episodes, a higher target of 0.8 to 1.0 mmol/L may be required.
• Monitoring Schedule: Measure serum lithium levels 5-7 days after initiation or any dose change. The blood sample must be taken exactly 12 hours after the evening dose (trough level) to ensure accuracy. Once stable, monitor levels every 3 to 6 months.
• Organ Toxicity Checks: Perform renal function tests (serum electrolytes, urea, creatinine, and eGFR) and thyroid function tests (TSH) every 3 to 6 months. Measure serum calcium annually to screen for lithium-induced hyperparathyroidism.

Lithium Toxicity

Lithium toxicity is a clinical emergency, often precipitated by dehydration, severe illness, or drug interactions that reduce renal clearance (specifically NSAIDs, ACE inhibitors, ARBs, and thiazide diuretics). You must recognise the signs of toxicity:

• Mild-to-moderate (levels 1.5 - 2.0 mmol/L): Apathy, lethargy, coarse hand tremor, muscle weakness, ataxia, vomiting, diarrhoea.
• Severe (levels > 2.0 mmol/L): Hyperreflexia, nystagmus, convulsions, renal failure, cardiac arrhythmias, coma, death.

Suicide Risk Assessment and Safety Planning

Suicide risk assessment is a core clinical skill that is heavily blueprinted in the KFP exam. Examiners expect you to outline a structured risk assessment, document clinical rationale, and construct a collaborative safety plan.

1. Structured Risk Assessment

When assessing a patient with active suicidal ideation, you must systematically evaluate and document both risk and protective factors:

• Suicidal Ideation: Assess frequency, duration, intensity, and whether the patient can resist the thoughts.
• Plan and Intent: Determine if the patient has a specific plan, access to lethal means (e.g. stockpiling medications, firearms), and the intent to act on the plan.
• Risk Factors: History of previous suicide attempts (the strongest predictor), active depressive or psychotic illness, substance abuse, severe hopelessness, recent discharge from psychiatric inpatient care, and severe psychosocial stressors.
• Protective Factors: Strong family support networks, young children at home, religious or moral objections to suicide, active engagement with mental health services, and future-oriented goals.

2. Collaborative Safety Planning

For patients identified as low-to-moderate risk who can be managed in the community, you must construct a structured, written safety plan. Do not rely on vague "contracts for safety," which are clinically ineffective. The safety plan should include:

• Recognising warning signs: Document personal triggers or changes in mood/behaviour that indicate a crisis is developing.
• Internal coping strategies: Actions the patient can take independently to distract themselves.
• Social contacts for distraction: Friends or family members the patient can contact to distract them.
• People to contact for help: Specific trusted individuals the patient can explicitly tell they are in crisis.
• Professional services: Direct phone numbers for Lifeline (13 11 14), Beyond Blue, their GP, or the local mental health triage team.
• Making the environment safe: Explicit steps to remove lethal means.

If a patient is determined to be at high immediate risk, arrange immediate emergency psychiatric assessment. If the patient refuses voluntary admission, utilize local mental health legislation to initiate an involuntary assessment.

Top 5 Examiner-Reported Mental Health Errors

Official RACGP public exam reports highlight specific recurring mistakes that candidates make in psychiatric questions. Reviewing these errors will prevent you from losing straightforward marks.

1. 1
   Ordering Outpatient Review for High Immediate Suicide Risk

   Candidates frequently select "urgent outpatient psychiatrist referral" or "arrange review in 1 week" for a patient presenting with active intent to commit suicide, a detailed plan, and access to lethal means. This is a severe clinical safety error. Any patient at immediate high risk of suicide must be kept in a safe clinic environment, and arrangements made for immediate emergency transfer.

2. 2
   Prescribing Antidepressant Monotherapy in Bipolar Disorder

   Candidates often select immediate SSRI therapy for a patient presenting with depressive symptoms without reviewing their psychiatric history for manic or hypomanic episodes. In a patient with underlying bipolar disorder, antidepressant monotherapy can trigger a manic switch, increase suicidal agitation, or precipitate rapid cycling. A mood stabilizer must be initiated.

3. 3
   Neglecting 12-Hour Trough Rule for Lithium Blood Tests

   When asked to specify the instructions for monitoring lithium levels, candidates often write "perform a blood test in the morning" or fail to specify the timing. Lithium levels must be taken exactly 12 hours after the previous evening dose (trough level) to ensure clinical validity. Failing to specify this in a KFP exam will lose marks.

4. 4
   Co-Prescribing SSRIs and Tramadol

   In pharmacological management questions, candidates frequently select tramadol for pain management in a patient who is already taking an SSRI. Tramadol inhibits the reuptake of serotonin and carries a high risk of precipitating serotonin syndrome when combined with SSRIs. Complementary non-serotonergic analgesia should be selected.

5. 5
   Relying on "Contracts for Safety" in Suicide Management

   Candidates under exam pressure often select "obtain a verbal contract for safety" as the primary risk-mitigation strategy for a suicidal patient. Official exam reports state that "contracts for safety" are clinically outdated and lack evidence. Instead, candidates must detail a comprehensive, collaborative safety plan.

Frequently Asked Questions