PLAB 1 Psychiatry — Questions and Answers
Question 1: A 35-year-old man is brought to A&E by police under Section 136 of the Mental Health Act 1983. He is hearing voices telling him to harm himself. Which section of the Mental Health Act allows for assessment and admission for up to 28 days?
- Section 2 (Correct answer)
- Section 3
- Section 4
- Section 5(2)
Correct answer: Section 2
Section 2 of the Mental Health Act 1983 (amended 2007) allows compulsory admission for assessment (and treatment necessary for assessment) for up to 28 days. It requires two medical recommendations and an approved mental health professional (AMHP) application.
Question 2: A 25-year-old woman presents with low mood, anhedonia, early morning wakening, poor concentration, and feelings of worthlessness for the past 4 weeks. She has no suicidal ideation. According to NICE guidelines, what is the first-line treatment for moderate depression?
- Immediate referral to secondary care psychiatry
- A high-intensity psychological intervention (CBT) or an SSRI antidepressant such as sertraline (Correct answer)
- Benzodiazepines for anxiety and sleep
- Electroconvulsive therapy
Correct answer: A high-intensity psychological intervention (CBT) or an SSRI antidepressant such as sertraline
NICE guidelines (NG222) recommend offering either a high-intensity psychological therapy (such as CBT) or an SSRI antidepressant (sertraline or fluoxetine as first choice) for moderate depression. The choice should be based on shared decision-making with the patient.
Question 3: A 20-year-old man presents with a 6-month history of auditory hallucinations (third-person commentary), thought insertion, and social withdrawal. There is no history of substance misuse. What is the most likely diagnosis?
- Bipolar affective disorder
- Schizophrenia (Correct answer)
- Schizoaffective disorder
- Drug-induced psychosis
Correct answer: Schizophrenia
First-rank symptoms (Schneider's) — including third-person auditory hallucinations and thought insertion — persisting for over one month in the absence of substance misuse or organic cause, are characteristic of schizophrenia. The 6-month duration with social decline supports this diagnosis under ICD-11 criteria.
Question 4: A patient on clozapine presents with a sore throat and fever. His blood results show a white cell count of 1.2 x10^9/L and neutrophils of 0.3 x10^9/L. What is the most important immediate action?
- Continue clozapine and prescribe antibiotics
- Stop clozapine immediately, admit the patient, and arrange urgent haematology review (Correct answer)
- Reduce the clozapine dose by half
- Reassure the patient and repeat bloods in 1 week
Correct answer: Stop clozapine immediately, admit the patient, and arrange urgent haematology review
Clozapine can cause agranulocytosis (neutrophils <0.5 x10^9/L), a potentially fatal side effect. Clozapine must be stopped immediately and never restarted. The patient needs urgent admission, barrier nursing, blood cultures, and broad-spectrum antibiotics. Regular blood monitoring is mandatory for all patients on clozapine.
Question 5: According to NICE guidelines, what is the first-line pharmacological treatment for generalised anxiety disorder (GAD) if psychological interventions have been tried?
- Diazepam
- Sertraline (SSRI) (Correct answer)
- Olanzapine
- Lithium
Correct answer: Sertraline (SSRI)
NICE recommends SSRIs (sertraline is first choice) as first-line pharmacological treatment for GAD. Benzodiazepines should not be offered beyond short-term crisis use (maximum 2-4 weeks) due to dependence risk. If the SSRI is not tolerated, an SNRI (duloxetine or venlafaxine) or pregabalin may be considered.
Question 6: A 19-year-old woman with a BMI of 14.5 presents with amenorrhoea, lanugo hair, and an intense fear of gaining weight despite being significantly underweight. What is the most likely diagnosis?
- Bulimia nervosa
- Anorexia nervosa (Correct answer)
- Body dysmorphic disorder
- Depression with weight loss
Correct answer: Anorexia nervosa
Anorexia nervosa is characterised by significantly low body weight (BMI <17.5 or <85% expected), intense fear of weight gain, and disturbed body image. Physical signs include amenorrhoea, lanugo hair, bradycardia, and hypothermia. A BMI of 14.5 indicates severe anorexia requiring urgent medical and psychiatric assessment.
PLAB 1 Psychiatry
A 35-year-old man is brought to A&E by police under Section 136 of the Mental Health Act 1983.
He is hearing voices telling him to harm himself.
Which section of the Mental Health Act allows for assessment and admission for up to 28 days?