First-Known Hypnopompic Hallucination Occurring In-Hospital: Case Report

Hypnopompic hallucinations (upon waking) and hypnagogic hallucinations (before sleep) are common in the general population, yet no English-language reports describe hospital staff observing them. These hallucinations are normal phenomena but also characteristic of narcolepsy and can be triggered by certain medications. They occur more often in people with psychiatric conditions: those with anxiety, depression, or bipolar disorder have a twofold increase in weekly episodes, and those with adjustment disorders a 1.5-fold increase. Lifetime incidence varies widely in the literature (hypnopompic 6–13%, hypnagogic 25–38%). Over half of people who experience them have no associated disorder. The authors recommend careful interviewing when hallucinations first appear in someone unaware of them, to screen for sleep disorders.

Study at a glance

Abstract

Despite the high prevalence of hypnopompic hallucinations in the community, to our knowledge there are no reports that have been published in the English literature of these phenomenon observed by staff in the hospital setting. Psychiatric or neurological evaluation often ensues if a patient reports hallucinations in other circumstances, but when they are reported in connection with sleep, further evaluation is rarely performed because such events are common in the general populace. Our report emphasizes the distinction between hypnopompic and hypnagogic hallucination as an ongoing feature of life that someone is aware of, which we believe to be the case for normal persons who have them, and a similar hallucination occurring for the first time in someone who is unaware of it, at least unable to remember it. In the latter instance, we suggest careful interview for symptoms of a sleep disorder. Hypnagogic (prior to sleep onset) and hypnopompic (upon arousal from sleep) hallucinations are both phenomena that occur in normal people and symptoms that are characteristic of narcolepsy (1, 2). They are a common occurrence, experienced by almost everyone at least once and have also been shown to be associated with the use or withdrawal from certain medications, specifically, tricyclic antidepressants, opiates, and donepezil (3-5). Although hypnopompic and hypnagogic hallucinations are generally considered to be normal phenomenon, they have increased incidence in several psychiatric and neurologic disorders (6). One study of over 14,000 subjects revealed that people with anxiety, depression, or bipolar affective disorder have a two-fold increase in experiencing hypnopompic or hypnagogic hallucinations at least once weekly. The same study showed that people with adjustment disorders have a 1.5fold increase in experiencing these phenomenon at least once weekly (6-8). The notion that such phenomena are normal may be part of the reason behind the wide variation in the literature with regard to their lifetime incidence (hypnopompic 6-13%, hypnagogic 25–38%) (4, 9-11). Over 50 percent of people who experience them have no