Dreams, Oneirophrenia and Dementia: Can a Clouded Dream-Wake Recognition Herald Cognitive Impairment?

The Merriam-Webster Dictionary Online defines dreams as a succession of ideas, pictures, or feelings that happen while people sleep (https://www.merriam-webster.com/dictionary/dream). The Sleep Foundation describes a dream as ideas or images that come to mind while people are asleep; a dream may occur at any sleep stage, but rapid eye movement (REM) sleep is when dreams tend to happen most often and vividly (https://www.sleepfoundation.org/dreams). According to a 2022 systematic review of 605 middle-aged individuals, having upsetting dreams was linearly and statistically linked to an increased risk of cognitive deterioration and an increased chance in older adults of developing dementia.[1] An article published by da Silva[2] in this journal highlighted that in older people and in those who have neurodegenerative illnesses, sleep disruption is common and predicts cognitive deterioration. In 1992, we introduced “oneirophrenia” to characterize dream alteration in persons with AIDS dementia complex.[3] The frequent comment we collect from persons affected by oneirophrenia and distressed by the experience is: “When I wake up, and for a while, I'm not sure whether I'm still dreaming or awake”.[3] Oneirophrenia is a word used by other authors to describe a condition in which people have difficulty telling the difference between reality and a dream, as if they were in a dreamlike state of awareness.[4] [5] We have also found oneirophrenia linked to early Alzheimer dementia, mild cognitive impairments, organic brain injuries, and during the resolution of delirium.[6] However, oneirophrenia has also been mentioned in people with catatonia and delirious mania.[7]