Many older adults have problems sleeping, but people with dementia often have an even harder time. Sleep disturbance may affect up to 25% of people with mild to moderate dementia and 50% of people with severe dementia. Sleep disturbances tend to get worse as dementia progresses in severity.
Possible sleep problems include excessive sleepiness during the day and insomnia with difficulty falling asleep and staying asleep. Frequent awakenings during the night and premature morning awakenings are also common.
People with dementia might also experience a phenomenon in the evening or during the night called sundowning. They might feel confused, agitated, anxious and aggressive. Night wandering in this state of mind can be unsafe.
Obstructive sleep apnea is also more common in people with Alzheimer's disease. This potentially serious sleep disorder causes breathing to repeatedly stop and start during sleep.
Factors that might contribute to sleep disturbances and sundowning include:
- Mental and physical exhaustion at the end of the day
- Changes in the body clock
- A need for less sleep, which is common among older adults
- Disorientation
- Reduced lighting and increased shadows, which can cause people with dementia to become confused and afraid