Investigators at Baylor University in Waco, Texas, found caregivers lost between 2.5 to 3.5 hours of sleep a week due to difficulty falling asleep and staying asleep.
"Losing 3.5 hours of sleep per week does not seem much, but caregivers often experience accumulation of sleep loss over years," said review lead author Chenlu Gao, a doctoral candidate of psychology and neuroscience.
"Losing 3.5 hours of sleep weekly on top of all the stress, grief and sadness can have a really strong impact on caregivers' cognition, and mental and physical health," Gao added in a university news release. But improving caregivers' sleep quality can significantly improve their functioning and quality of life, Gao said.
For example, the researchers found that caregivers' sleep noticeably improved after simple changes such as getting more morning sunlight, establishing a regular and relaxing bedtime routine, and doing moderate physical exercise.
Chronic stress can cause sleep problems, and nighttime awakenings by people with dementia can also disrupt caregivers' sleep, the researchers noted.
According to review co-author Michael Scullin, "With that extra bit of sleep loss every night, maybe a caregiver now forgets some medication doses or reacts more emotionally than he or she otherwise would." Scullin is an assistant professor of psychology and neuroscience, and director of the Baylor's Sleep Neuroscience and Cognition Laboratory.
"Caregivers are some of the most inspiring and hardest-working people in the world, but sleep loss eventually accumulates to a level that diminishes one's vigilance and multi-tasking," Scullin said.
For the report, the researchers reviewed 35 studies that included nearly 3,300 caregivers. The findings were published online recently in JAMA Network Open.
About 16 million family caregivers in the United States provide long-term care for dementia patients. Family members of people with dementia average nearly 22 hours a week of caregiving, according to the Alzheimer's Association.