A 70-year-old retired teacher reports falling asleep by 7 PM and waking spontaneously at 3 AM feeling fully refreshed. He is distressed because he cannot participate in evening social activities. Polysomnography is normal for his age. Which is the most likely diagnosis?
- A Major depressive disorder with early morning awakening
- B Advanced sleep-wake phase disorder ✓
- C Behaviourally induced insufficient sleep syndrome
- D Obstructive sleep apnoea causing sleep fragmentation
Correct answer: B. Advanced sleep-wake phase disorder
Explanation
Advanced sleep-wake phase disorder is characterized by an intractably early sleep onset and early morning awakening with otherwise normal sleep quality and duration. It is distinct from depression, where early morning awakening is accompanied by non-restorative sleep and depressed mood. The refreshed feeling upon waking and normal polysomnography exclude OSA and insufficient sleep.
Reference: International Classification of Sleep Disorders, 3rd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.