I am tired of the term 'sundowners' and suggestions of lighting and scheduling. Habits are developed by learning, or appeal. They must find something appealing about staying up all night, in the early stages of dementia. What are the fears then of the daytime hours? My mother knows who the family is and the difference between night and day, although "I had no idea it was so late!" is a common statement. Yet she continues to sleep from dawn until dusk, after piddling around the kitchen. We have gone on trips, and managed to "reschedule" her routine fairly easily, for that period. She will go to bed at a reasonable hour and wake up with the rest of us. Upon coming home, however it isn't long before she reverts back to staying up all night. There has to be something other than a screwed up internal clock, or confusing night and day. Certainly someone can postulate as to "why" and not just tell this is part and parcel of dementia/Alzheimers, and leave it at that.
When he first came to live, he also hardly ever slept.
system to the solar day. In fact, a carefully orchestrated light/dark pattern has been shown in several controlled studies of older populations, with and without ADRD, to be a powerful non-pharmacological tool to improve sleep efficiency and consolidation. Discussed their study are research results from studies looking at the effectiveness of light therapy in improving sleep, depression,
and agitation in older adults with ADRD. A 24-hour lighting scheme to increase circadian entrainment, improve visibility, and reduce the risk of falls in those with ADRD is proposed.
melatonin secretion by the pineal gland (or taken as a supplement)
core body temperature (night setback thermostats help)
plasma level of cortisol (helps raise blood sugar levels during stress).
Ambient light is also a factor, and modern living with electric lighting has a way of throwing off the rhythms too.