A 22-year-old man comes to the office due to irregular sleep for the past 3 months. The patient says, "School has become more stressful, and I have been feeling more fatigued since my girlfriend broke off our relationship last month." He is often sleepy during the day and sometimes falls asleep unintentionally during classes. The patient goes to bed at 1 AM and awakens at 9 AM. After classes, he avoids socializing and frequently returns straight to his dorm room to nap. The patient also describes "weird things happening as I fall asleep, like hearing whispering voices and seeing colorful animals." He describes another unusual experience last week when he suddenly felt weak in his face and knees following an upsetting phone call with his ex-girlfriend. The patient drinks beer socially but does not use illicit drugs. He has a history of depression as a teenager that responded to psychotherapy. Height is 170.2 cm (5 ft 7 in), and weight is 83.9 kg (185 lb). BMI is 29 kg/m². Physical examination is normal. Which of the following is the most likely diagnosis for this patient?

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11ec25c8_d763_7964_bc81_f9424076ecb9_MD0003_00 This patient's excessive daytime sleepiness with lapses into sleep (eg, unintentionally falling asleep in class), hallucinations while falling asleep, and cataplexy (transient loss of muscle tone in response to intense emotion) are suggestive of narcolepsy. Intrusions of REM sleep phenomena during sleep-wake transitions may include hypnagogic (on falling asleep) and hypnopompic (on awakening) hallucinations as well as sleep paralysis (inability to move immediately after awakening). Narcolepsy is associated with low cerebrospinal fluid levels of orexin-A/hypocretin-1. Onset typically occurs during adolescence or the early 20s. Diagnostic evaluation includes polysomnography to rule out other sleep disorders and a multiple sleep latency test that demonstrates decreased sleep latency and sleep-onset REM periods. (Choice A) Adjustment disorder would not explain this patient's hypnagogic hallucinations and cataplexy, which are characteristic of narcolepsy. (Choice B) A diagnosis of narcolepsy requires ruling out other sleep disorders that can present with excessive daytime sleepiness. Delayed sleep-wake phase disorder is characterized by a bedtime that is shifted later than desired with subsequent difficulty awakening at a socially, scholastically, or professionally mandated time, which results in shortened total sleep duration. This patient goes to sleep late (at 1 AM) but sleeps for a normal duration and does not describe an inability to awaken at a preferred time. (Choice C) Hypersomnolence disorder is characterized by persistent daytime sleepiness (not sleep attacks) and is diagnosed only when excessive sleepiness is not better explained by another sleep disorder. (Choice D) This patient is getting a sufficient amount of sleep with 8 hours of sleep plus naps. Insufficient sleep may lead to excessive daytime sleepiness, napping, and quicker REM onset, but it is not associated with cataplexy. (Choice E) This patient has insufficient symptoms for a current major depressive episode; his hallucinations are related to narcolepsy. major depressive episode Educational objective: Narcolepsy is characterized by excessive daytime sleepiness, cataplexy, and REM sleep-related phenomena (eg, hypnagogic/hypnopompic hallucinations, sleep paralysis). References: Central disorders of hypersomnolence: focus on the narcolepsies and idiopathic hypersomnia. (http://www.ncbi.nlm.nih.gov/pubmed/26149554) Narcolepsy: a clinical review. (http://www.ncbi.nlm.nih.gov/pubmed/24830461)

A 22-Year-Old Man Comes to the Office Due to Irregular