• Posted March 31, 2025

Bad Sleep Linked To Alzheimer's-Related Brain Changes

Certain stages of sleep – deep sleep and dream sleep – appear to contribute to brain health in ways that affect risk of Alzheimer’s disease, a new study says.

People who get less deep sleep or dream sleep have smaller volumes in critical brain regions, researchers reported today in the Journal of Clinical Sleep Medicine.

Lack of those types of sleep particularly appears to affect the inferior parietal region, which is known to undergo early changes in Alzheimer’s, researchers wrote.

“Our findings provide preliminary evidence that reduced neuroactivity during sleep may contribute to brain atrophy, thereby potentially increasing the risk of Alzheimer’s disease,” lead researcher Gawon Cho, a postdoctoral associate at Yale School of Medicine in New Haven, Conn., said in a news release.

“These results are particularly significant because they help characterize how sleep deficiency, a prevalent disturbance among middle-aged and older adults, may relate to Alzheimer’s disease pathogenesis and cognitive impairment,” Cho added.

For the study, researchers analyzed sleep data for 270 people. They specifically looked at how much time people spent in slow wave sleep – the deepest level of sleep – and their time spent in rapid eye movement (REM) sleep, or dream sleep.

The team then compared those sleep cycles to MRI brain scans taken 13 to 17 years later.

Results showed that less time spent in those sleep stages was linked to appreciably smaller volumes in some regions of the brain.

Prior research has shown that sleep deprivation alters metabolic activity in the inferior parietal region, which helps different areas of the brain work cooperatively, researchers said.

Such sleep deprivation also can affect cognitive performance involving that area of the brain.

“Sleep architecture may be a modifiable risk factor for Alzheimer’s disease and related dementias, posing the opportunity to explore interventions to reduce risk or delay Alzheimer’s onset,” Cho said.

However, further investigation is needed to fully understand the causal relationships between sleep cycles and Alzheimer’s disease progression.

More information

The Cleveland Clinic has more about the parietal lobe.

SOURCE: American Academy of Sleep Medicine, news release, March 31, 2025