A 25-year-old patient presents with episodes of screaming during sleep. They occur in the early part of the night, and the patient has no recollection of the events the next morning.
Which of the following suggests a night terror rather than a nightmare?
A. Occurs during non-REM sleep
B. Occurs in stage 2 sleep
C. Occurs during later stages of REM sleep
D. Associated with enuresis
E. There is partial recall of the event the next day
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✅ Correct Answer: A. Occurs during non-REM sleep
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🧩 Explanation (exam-focused, structured)
➤ Why A is correct:
• Night terrors are parasomnias arising from deep NREM sleep (Stage 3)
• Occur in the first third of the night
• Brain is in slow-wave sleep → not dreaming → no recall
• This is the single most specific distinguishing feature
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➤ Why the other options are wrong:
B. Occurs in stage 2 sleep
• Stage 2 = light NREM sleep
• Night terrors occur in Stage 3 (deep sleep)
• ❗ Common trap: confusing NREM stages
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C. Occurs during later stages of REM sleep
• This describes nightmares
• REM sleep = dreaming stage
• Occurs in last third of night
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D. Associated with enuresis
• Can occur in night terrors, BUT:
• Not specific
• Not diagnostic
• ❗ Exam rule: choose core defining feature, not association
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E. There is partial recall of the event the next day
• Suggests nightmares
• Night terrors = complete amnesia
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📘 NICE / ICD / Exam Concept
This question tests:
➡️ Parasomnia classification (REM vs NREM)
• NREM parasomnias:
• Night terrors
• Sleepwalking
• Confusional arousals
• REM parasomnias:
• Nightmares
• REM sleep behaviour disorder
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🔑 High-yield comparison
Night terrors:
• NREM (Stage 3)
• First third of night
• No recall
• Difficult to wake
• Autonomic arousal (tachycardia, sweating)
Nightmares:
• REM sleep
• Last third of night
• Vivid recall
• Easily woken
• Often linked to PTSD
A 79-year-old man presents with insomnia and requests medication to help him sleep. He has no other acute psychiatric symptoms.
Which of the following medications should be avoided in this patient?
A. Diazepam
B. Lorazepam
C. Zopiclone
D. Zolpidem
E. Oxazepam
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✅ Correct answer
Diazepam
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3️⃣ Clear, exam-focused explanation
Why diazepam is correct:
• Long half-life → drug accumulation in elderly
• Active metabolites → prolonged sedation
• ↑ risk of:
→ Falls
→ Confusion
→ Delirium
Why others are wrong:
• Lorazepam / Oxazepam
→ Shorter acting
→ No active metabolites
→ Safer in elderly (still caution)
• Zopiclone / Zolpidem
→ “Z-drugs”
→ Recommended for short-term insomnia
→ Less accumulation (but still risk)
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4️⃣ 📘 NICE / ICD-11 / Maudsley / BNF rules
• NICE insomnia guidance:
→ Use non-pharmacological first
→ If needed → short-term hypnotics
• BNF / Maudsley:
→ Avoid long-acting benzodiazepines in elderly
→ Prefer short-acting agents
Exam is testing → Contraindication / prescribing in elderly
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5️⃣ ⭐ High-yield facts to memorise
• Diazepam half-life: 20–100 hours (+ active metabolites)
• Elderly → ↓ hepatic metabolism → accumulation
• “LOT” drugs safer:
→ Lorazepam, Oxazepam, Temazepam
• Z-drugs = first-line short-term pharmacological option
• Benzos → ↑ falls + delirium risk in elderly
Melatonin is prescribed for a child with a neurodevelopmental disorder and sleep difficulties.
Which of the following is most significantly improved by melatonin?
A. Sleep onset latency
B. Sleep duration
C. REM onset latency
D. Sleep apnoea
E. Number of night-time awakenings
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2️⃣ ✅ Correct answer
Sleep duration
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3️⃣ Clear, exam-focused explanation
Why sleep duration is correct:
• Melatonin improves:
→ Total sleep time (duration)
• Especially effective in:
→ Neurodevelopmental disorders (e.g. autism, ADHD)
What melatonin also does (but less tested):
• ↓ Sleep onset latency
• ↓ Night awakenings
→ BUT exam asks “most significantly increases”
Why others are wrong:
• Sleep onset latency
→ Improved, but not the main measurable outcome
• REM onset latency
→ Not clinically targeted
• Sleep apnoea
→ No role
• Night awakenings
→ May reduce, but less significant than duration
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4️⃣ 📘 NICE / ICD-11 / Maudsley / BNF rules
• Melatonin:
→ Used in children with neurodevelopmental disorders
• NICE:
→ Consider if behavioural strategies insufficient
Exam is testing → Management (sleep pharmacology effects)
⸻
5️⃣ ⭐ High-yield facts to memorise
• Melatonin:
→ Regulates circadian rhythm
• Effects:
→ ↑ sleep duration
→ ↓ sleep latency
→ ↓ awakenings
• Particularly useful in:
→ Autism
→ ADHD
• Modified-release often used
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6️⃣ ⚠️ Common MRCPsych exam traps
• Choosing sleep latency ❌ (tempting distractor)
• Thinking melatonin treats sleep apnoea ❌
• Overfocusing on REM sleep ❌
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7️⃣ 🧠 One-line exam answer
Melatonin most significantly increases total sleep duration in children with neurodevelopmental disorders.
A 4-year-old boy is brought to clinic due to episodes of sleepwalking. His mother asks about typical features of this condition.
Which of the following statements is incorrect regarding sleepwalking?
A. It seems to run in families
B. Sleepwalking is common in children
C. Injury may occur during sleepwalking
D. Child usually wakes up during sleepwalking
E. It typically occurs between ages 4 and 8
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2️⃣ ✅ Correct answer
Child usually wakes up during sleepwalking
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3️⃣ Clear, exam-focused explanation
Why this is correct (i.e. incorrect statement):
• Sleepwalking = partial arousal from deep sleep (NREM stage 3)
• Child is:
→ Not fully conscious
→ Difficult to wake
• If awakened:
→ Confused / disoriented
• Typically no recall next morning
Why others are correct:
• Runs in families
→ Strong genetic association
• Common in children
→ Up to ~20% experience it
• Injury may occur
→ Walking, climbing, leaving house
• Age 4–8 peak
→ Classic exam age range
⸻
4️⃣ 📘 NICE / ICD-11 / Maudsley / BNF rules
• ICD-11: Disorders of arousal (NREM parasomnias)
→ Sleepwalking occurs during deep sleep
→ Impaired awareness
Exam is testing → Diagnosis / phenomenology of parasomnias
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5️⃣ ⭐ High-yield facts to memorise
• Sleepwalking = NREM parasomnia (stage 3)
• Occurs in first third of night
• No dream recall
• Child appears awake but is not
• More common in children → improves with age
Tom, aged 12, has been diagnosed with NREM sleep disorder. The most likely diagnosis is;
A. Sleep walking
B. Sleep Bruxism
C. REM behavioural disorder
D. Nightmares
E. Sleep paralysis
⸻
✅ Correct answer: Sleep walking
⸻
💡 Explanation
👉 NREM parasomnias occur in deep sleep (stage 3/4)
👉 Why sleepwalking?
• Occurs in children
• Happens in deep NREM sleep
• Patient:
• Ambulates
• Confused
• Amnesia afterwards
⸻
🔥 High-yield features of NREM
• Occur in first third of night
• No recall
• Associated with:
• Sleep deprivation
• Stress
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⚠️ Exam traps
❌ Nightmares → REM
❌ Sleep paralysis → REM
❌ REM behaviour disorder → older males (Parkinson’s link)
25-year-old has excessive daytime sleepiness, sudden muscle weakness triggered by laughter, and sleep paralysis. What is the most likely diagnosis?
A. REM sleep behaviour disorder
B. Obstructive sleep apnoea
C. Narcolepsy with cataplexy
D. Night terrors
E. Insomnia
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✅ Correct answer: C. Narcolepsy with cataplexy
⸻
💡 Explanation
• Classic tetrad:
Sleepiness
Cataplexy (emotion-triggered)
Sleep paralysis
Hypnagogic hallucinations
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🎯 High-yield stressors
• Cataplexy = pathognomonic
• Associated with:
HLA-DQB1*0602 (DR2)
Which HLA type is strongly associated with narcolepsy with cataplexy?
A. HLA-B27
B. HLA-DR3
C. HLA-DQB1*0602
D. HLA-A1
E. HLA-DR4
⸻
✅ Correct answer: C. HLA-DQB1*0602
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🔥 Stressors
• Seen in ~95% of cases
• Strong genetic association
What is the first-line treatment for excessive daytime sleepiness in narcolepsy?
A. Fluoxetine
B. Clonazepam
C. Modafinil
D. Propranolol
E. Lithium
⸻
✅ Correct answer: C. Modafinil (Provigil)
⸻
💡 Explanation
• Wakefulness-promoting agent (eugeroic)
It enhances alertness and cognitive function by increasing dopamine, norepinephrine, and histamine in the brain.
⸻
🔥 Stressors
• Also:
Pitolisant
Sodium oxybate
What is the treatment for cataplexy in narcolepsy?
A. Antipsychotics
B. Antidepressants
C. Benzodiazepines
D. Beta-blockers
E. Mood stabilisers
⸻
✅ Correct answer: B. Antidepressants
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💡 Explanation
• Suppress REM → reduce cataplexy
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🔥 Stressors
• SSRIs / SNRIs / TCAs
• Sodium oxybate also effective
🔥 HIGH-YIELD PAPER B STRESSORS
• 💣 Cataplexy = ONLY symptom specific to narcolepsy
• 💣 Triggered by emotion (laughter, surprise, anger)
• 💣 Consciousness preserved (NOT seizure)
⸻
⚠️ EXAM TRAPS
• Modafinil → treats sleepiness, NOT cataplexy
• Clonazepam → for REM behaviour disorder, NOT narcolepsy
A 70-year-old man acts out vivid dreams, shouting and punching during sleep. What is the most likely diagnosis?
A. Night terrors
B. REM sleep behaviour disorder
C. Narcolepsy
D. Sleepwalking
E. PTSD
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✅ Correct answer: B. REM sleep behaviour disorder
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💡 Explanation
• Loss of REM atonia → motor activity during dreams
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🔥 HIGH-YIELD STRESSORS
• 💣 Strongly linked to neurodegeneration
Parkinson’s disease
Lewy body dementia
• 💣 80% develop neurodegenerative disease within ~10 years
What is the first-line treatment for REM sleep behaviour disorder?
A. Diazepam
B. Clonazepam
C. Zopiclone
D. Melatonin only
E. Fluoxetine
⸻
✅ Correct answer: B. Clonazepam
⸻
💡 Explanation
• Reduces motor activity during REM
⸻
🔥 HIGH-YIELD STRESSORS
• 💣 Clonazepam = gold standard
• 💣 Melatonin = alternative (elderly / fall risk)
⸻
⚠️ EXAM TRAPS
• Benzos generally avoided in elderly → BUT clonazepam still first-line here
A 6-year-old wakes screaming, inconsolable, with no memory of the event the next day. What is the diagnosis?
A. Nightmares
B. REM sleep behaviour disorder
C. Night terrors
D. Sleep paralysis
E. Dissociative disorder
⸻
✅ Correct answer: C. Night terrors
⸻
💡 Explanation
• NREM parasomnia → no recall
⸻
🔥 HIGH-YIELD STRESSORS
• 💣 Occurs in first third of night
• 💣 Child appears terrified but cannot be comforted
• 💣 No memory next day
A patient with insomnia has been taking zopiclone long-term. What is the most appropriate next step?
A. Increase dose
B. Switch to benzodiazepine
C. Sleep hygiene education
D. Add antipsychotic
E. Start SSRI
⸻
✅ Correct answer: C. Sleep hygiene education
⸻
💡 Explanation
• Always address behavioural factors first
⸻
🔥 HIGH-YIELD STRESSORS
💣 CBT-I = first-line
💣 Z-drugs:
Short-term only
Dependence risk
⸻
⚠️ EXAM TRAPS
• Do NOT escalate hypnotics
• Do NOT switch to benzos → worse
Which benzodiazepine is safest in liver impairment?
A. Diazepam
B. Chlordiazepoxide
C. Lorazepam
D. Clonazepam
E. Alprazolam
⸻
✅ Correct answer: C. Lorazepam
⸻
💡 Explanation
• No active metabolites → safer in liver disease
⸻
🔥 HIGH-YIELD STRESSORS
💣 LOT drugs = SAFE in liver disease
• Lorazepam
• Oxazepam
• Temazepam
⸻
⚠️ EXAM TRAPS
• Diazepam → long half-life → accumulates
A 52-year-old obese man snores loudly and has daytime sleepiness. His partner reports apnoeic episodes. What is the diagnosis?
A. Narcolepsy
B. REM sleep behaviour disorder
C. Obstructive sleep apnoea
D. Insomnia
E. Panic disorder
⸻
✅ Correct answer: C. Obstructive sleep apnoea
⸻
💡 Explanation
• Repeated airway obstruction during sleep
⸻
🔥 HIGH-YIELD STRESSORS
• 💣 Risk factors:
Obesity
Large neck circumference
• 💣 Complications:
Hypertension
Stroke
Depression
⸻
⚠️ EXAM TRAPS
• Daytime sleepiness ≠ always narcolepsy
→ check snoring + apnoea
What effect does sleep deprivation have on seizure threshold?
A. Increases threshold
B. No effect
C. Lowers threshold
D. Prevents seizures
E. Only affects REM
⸻
✅ Correct answer: C. Lowers threshold
⸻
💡 Explanation
• Sleep deprivation → neuronal instability
⸻
🔥 HIGH-YIELD STRESSORS
• 💣 Used in EEG to provoke seizures
• 💣 Common trigger in epilepsy
Which sleep stage is associated with sleepwalking?
A. REM
B. Stage 1
C. Stage 2
D. Stage 3 (slow-wave sleep)
E. Awake
⸻
✅ Correct answer: D. Stage 3
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💡 Explanation
• Deep NREM sleep parasomnia
⸻
🔥 HIGH-YIELD STRESSORS
• 💣 Occurs early night
• 💣 More common in children
• 💣 No recall
A patient with narcolepsy is on modafinil but continues to have cataplexy. What should be added?
A. Benzodiazepine
B. Antipsychotic
C. Antidepressant
D. Lithium
E. Beta-blocker
⸻
✅ Correct answer: C. Antidepressant
⸻
💡 Explanation
• Suppresses REM → reduces cataplexy
⸻
🔥 HIGH-YIELD STRESSORS
• 💣 Modafinil → sleepiness
• 💣 Antidepressants → cataplexy
A 22-year-old woman with a history of traumatic brain injury presents with abnormal limb movements during sleep, described as flailing during REM sleep. Neurological examination is otherwise unremarkable.
Damage is suspected in a structure located in the dorsolateral pons near the lateral fourth ventricle, which is responsible for regulating muscle atonia during REM sleep.
Which neurotransmitter is primarily released from this structure?
A. Norepinephrine
B. Acetylcholine
C. Dopamine
D. Serotonin
E. GABA
⸻
✅ Correct answer
A. Norepinephrine
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3️⃣ 🧾 Clear, exam-focused explanation
✅ Why norepinephrine is correct:
• Structure described = locus coeruleus (LC)
• Location: dorsolateral pons near 4th ventricle
• LC is the main noradrenergic nucleus in the brain
• Functions:
• Regulates arousal and REM sleep
• Involved in muscle tone suppression during REM
• Damage → REM behaviour disorder (RBD)
• Loss of atonia → acting out dreams → flailing
⭐ High-yield facts to memorise
• Locus coeruleus = main noradrenaline source in brain
• Located in pons (blue spot — “coeruleus” = blue)
• REM sleep:
↓ norepinephrine activity
↓ serotonin activity
↑ acetylcholine
• REM Behaviour Disorder:
Seen in Parkinson’s, Lewy body dementia
• LC involved in:
Attention
Stress response
Memory consolidation
The main rationale to use melatonin in children with sleep disorders is to:
A. Alter sleep wake cycle
B. Reduce sleep latency
C. Increase sleep latency
D. Promote daytime sleep episodes
E. Increase duration of sleep
⸻
✅ Correct answer:
👉 B. Reduce sleep latency
⸻
🔍 Explanation (EXAM LOGIC)
👉 Melatonin = “sleep onset hormone”
💥 Main effect:
• Helps you fall asleep faster
→ ↓ sleep latency (time taken to fall asleep)
⸻
❌ Why others are wrong:
• A. Alter sleep wake cycle ❌
→ partially true (circadian role), BUT
👉 NOT the main exam-tested effect
