Vivid dream experiences are common among intensive care unit (ICU) patients and often carry a negative emotional impact. In a retrospective survey of 80 adults previously admitted to the ICU for at least four days or due to COVID-19, 79% reported dream experiences, with 73% describing them as life-like, 49% associating them with negative emotions, and 54% saying the dreams affected them even after waking. Dream content frequently related to the ICU admission. Younger age and longer ICU stay were linked to vivid dreams. Many participants also experienced delirium or perceptual disturbances, and some had difficulty distinguishing these from dreams. The findings suggest that providing anticipatory support may help patients process these experiences during recovery.
A distinctive feature of narcolepsy, termed 'dream delusions,' occurs when patients mistake the memory of a vivid dream for a real experience and form sustained false beliefs that can persist for days or weeks. In interviews with 46 narcolepsy patients with cataplexy and 41 healthy controls at academic medical centers in Boston and Leiden, dream delusions were surprisingly common and often severe, differing from fleeting hypnagogic or hypnopompic hallucinations. These false memories suggest source memory deficits in narcolepsy that have not yet been fully characterized.
Hypnagogic hallucinations in narcolepsy are multisensory and holistic, unlike the predominantly verbal-auditory hallucinations in schizophrenia. Among 60 narcolepsy patients, 102 schizophrenia patients, and 120 matched controls, psychotic symptoms such as delusions were no more frequent in narcolepsy than in controls, and the prevalence of formal psychotic disorders was not increased. Almost half of narcoleptics reported moderate interference with functioning due to hypnagogic hallucinations, mostly from related anxiety. These phenomenological differences aid in differential diagnosis.