I just found a some curious case reports on two people who had hallucinations in everyday life owing to unrecognised narcolepsy, but not realising it, they assumed their hallucinated episodes had genuinely occurred.
Unlike in psychosis, where affected people often believe that their hallucinations are real, people who have narcolepsy and have hallucinations are usually able to realise they were triggered by the condition.
In this case, the people were unaware that they had a tendency to hallucinate and so the boundaries between hallucination and reality began to blur.
The 45-year-old technical manager had a multi-year history of daytime sleepiness… He frequently had curious experiences during the day ‚Äì the neighbour throwing litter into the patient’s bin; his wife throwing precious objects away. Sometimes he saw himself trying to clean dirt on the side of a ditch. These memories and experiences were confusing. They gave rise to a surprised and suspicious state of mind.
Improbable and incomprehensible things happened, leaving him in doubt. Sometimes he gave sensitive-paranoid interpretations to the events, he also denounced the neighbour for filling his bin. His paranoidity drove his psychiatrist to the diagnostic conclusion of a delusional psychosis.
Recently he had a severe conflict with his chief on account of a vivid experience of having had sexual intercourse with the chief’s wife, which he mentioned to colleagues. Remembering every detail, he was convinced that his story was true, but the reactions of those around him gradually convinced him that this experience could be a hallucination.
The man was eventually referred to a sleep clinic, diagnosed with narcolepsy and successfully treated.
The other case is of a young woman who hallucinated that she had been sexually assaulted on a bus – an experience so vivid that she reported it to the police with numerous details of the offender.
She later realised that that she could have been wrong and as part of the court case for making a false police report she was medically assessed and also diagnosed with narcolepsy after a sleep lab assessment.
Link to PubMed entry for case reports.