Recent findings published by Jin and colleagues (2025) show that changes in sleep may be an early sign of Alzheimer’s disease. Sleep disturbances affecting sleep duration and sleep quality have previously been reported in Alzheimer’s disease, where sleep metrics are linked to neural biomarkers of the illness, including amyloid beta deposition, as assessed using positron emission tomography (Insel et al., 2021).

Jin et al., (2025), recently published in Alzheimer’s and Dementia, investigated whether changes in rapid eye movement may also be implicated in the disease process. Rapid-eye moment (REM) sleep plays a key role in learning and memory consolidation. Therefore, a delay in REM sleep is thought to interfere with memory and learning.

Jin et al., (2025) included 64 individuals with Alzheimer’s disease, 41 individuals with mild cognitive impairment and 23 individuals with normal cognition. Authors divided participants into two groups, including individuals entering REM sleep 98 minutes after falling asleep and individuals entering REM sleep more than 193 minutes after falling asleep. Authors found that individuals with long delays in REM sleep had higher levels of two toxic proteins seen in Alzheimer’s disease, including higher levels of amyloid beta in the brain, as well as higher levels of plasma p-tau181.

Authors suggested that prolonged delays in REM sleep may be a risk factor for Alzheimer’s disease. However, the design of the study is not able to determine causality. Therefore, the relationship between REM sleep and neural markers of Alzheimer’s disease could also be explained by the effects of neurodegeneration, whereby neurodegeneration negatively impacts cholinergic signalling, which may in turn disrupt REM sleep. Nevertheless, these findings highlight a key relationship between sleep and brain health.

The full-text article can be found here: https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.14495

References

Insel, P.S., Mohlenhoff, B.S., Neylan, T.C., Krystal, A.D., Mackin, R.S.. (2021). Association of Sleep and β-Amyloid Pathology Among Older Cognitively Unimpaired Adults. JAMA Netw Open. 2021 Jul 1;4(7):e2117573.

Jin, J., Chen, J., Cavaillès, C., Yaffe, K., Winer, J., Stankeviciute, L., … & Leng, Y. (2025). Association of rapid eye movement sleep latency with multimodal biomarkers of Alzheimer’s disease.Alzheimer’s & Dementia, e14495.