Sleep
| Syndrome | A cluster of symptoms and signs that occur together and form a recognisable pattern | Depressive syndrome: low mood, anhedonia, poor sleep, guilt |
What our notes say
- | Syndrome | A cluster of symptoms and signs that occur together and form a recognisable pattern | Depressive syndrome: low mood, anhedonia, poor sleep, guilt | (Classification of Mental Disorders)
- | Serotonin (5-HT) | Mood, sleep, appetite, anxiety | SSRIs raise synaptic serotonin. (Introduction to Psychopharmacology)
- They can also cause dependence and complex sleep behaviours. (Introduction to Psychopharmacology)
- Biological: genes and family history, brain structure and chemistry, physical illness, medications, substances, sleep, pregnancy and hormones, injury. (Biopsychosocial Formulation)
- | Biological | Family history of depression; HIV or another chronic illness; head injury; alcohol, khat or cannabis use; steroid treatment; poor sleep; postpartum hormonal change | (Biopsychosocial Formulation)
- | Physical | Functioning of the body | Absence of disease, fitness, nutrition, sleep, freedom from pain | (Psychiatry, Sociology, Anthropology and Psychology)
Study material on Sleep
- Sleep Physiology Examination Paper
- Psychiatry Year 6 CAT: October 2023, violence, defence mechanisms, hallucinations and sleep, 20 MCQs
- Bipolar and Related Disorders
- Neurodevelopmental Disorders II: ADHD and Disruptive Behaviour
- Biopsychosocial Formulation
- Behavioural Sciences MCQs — December 2013 Paper I (Past Paper)
- MEDICAL PHYSIOLOGY II ESsays
- Paediatric History Taking and Physical Examination
- Neurodevelopmental Disorders I: Autism Spectrum Disorder and Intellectual Disability
- Endocrine and Metabolic Pathology MCQs for Medical Students
- Sleep Physiology Examination Paper MCQs
- Weekly Year 2: Physiology Exam - June 5, 2026 (Section A: MCQs)
Practice questions on Sleep
A 52-year-old obese man (BMI 38 kg/m²) presents with daytime somnolence, loud snoring, and morning headaches. His wife reports he stops breathing repeatedly during sleep. ABG shows mild hypoxaemia and hypercapnia. Polysomnography shows apnoea-hypopnoea index (AHI) of 38 events/hour. Most likely diagnosis?
- Central sleep apnoea
- Cheyne-Stokes respiration
- Obstructive sleep apnoea
- Obesity hypoventilation syndrome
Answer: C. Obesity + snoring + witnessed apnoeas + daytime somnolence + AHI greater than 30 = severe OSA. Upper airway collapse during sleep causes repetitive hypoxaemia, hypercapnia, and arousal. ---
Sleep spindles are characteristic of which stage of NREM sleep?
- Stage 1
- Stage 2
- Stage 3
- REM sleep
- Mostly unchanged in early disease
Answer: B. Sleep spindles (10-14 Hz bursts) are the defining feature of Stage 2 NREM sleep, generated by the thalamic reticular nucleus. ---
PGO spikes during REM sleep originate from
- PGO spikes
- Parietal → Geniculate → Occipital cortex
- Pons → Globus pallidus → Occipital cortex
- Pineal → Geniculate → Occipital cortex
- Occurs only after chronic exposure
Answer: A. PGO spikes are generated in the pons and travel through the lateral geniculate nucleus to the occipital cortex, marking REM sleep onset. ---
Which neurotransmitter is inhibitory and promotes sleep when released from the preoptic area?
- Glutamate
- Histamine
- GABA
- Orexin
- Primarily an incidental laboratory finding
Answer: C. GABA neurons in the preoptic area of the hypothalamus are sleep-promoting and inhibit arousal systems. ---
The approximate duration of a complete sleep cycle is
- 60 minutes
- 90 minutes
- 120 minutes
- 150 minutes
- Usually mediated by non-specific mechanisms
Answer: B. Sleep cycles average 90 minutes, with 4-6 cycles occurring during a typical 8-hour sleep period. ---
Which of the following is characteristic of REM sleep?
- High muscle tone
- Slow eye movements
- Muscle atonia
- High-amplitude EEG waves
- Occurs only after chronic exposure
Answer: C. REM sleep is characterized by muscle atonia to prevent acting out dreams. ---