The "sweet spot" of sleep: too little or too much sleep will cause cognitive decline

Like many other good things in life, moderate sleep is best

Poor sleep quality and Alzheimer's disease are both related to cognitive decline, and distinguishing the effects of the two has proven to be a challenge

These findings were published in the " Brain " magazine today (October 20, 2021)

"Determining the relationship between sleep and the different stages of Alzheimer's disease has always been a challenge, but this is what you need to know in order to start designing interventions," said lead author Brendan Lucey, MD, who is the University of Washington Sleep Medicine Associate Professor of Neurology at the Center

Alzheimer's disease is the main cause of cognitive decline in the elderly, and about 70% of dementia cases are related to this

In order to clarify the different effects of sleep and Alzheimer’s disease on cognition, Lucy and her colleagues recruited some volunteers who participated in Alzheimer’s through the Charles F.

In total, the researchers obtained sleep and Alzheimer's disease data for 100 participants.

Researchers found a U-shaped relationship between sleep and cognitive decline

The U-shaped relationship is also applicable when measuring specific sleep stages, including rapid eye movement (REM), which is dreaming, and non-rapid eye movement sleep

"It is particularly interesting that not only people who sleep for a short time, but also people who sleep for a long time have a greater decline in cognitive ability," said David Holtzman, MD, professor of neurology and senior co-author

Everyone’s sleep needs are unique, and those who wake up feeling short or long should not be forced to change their habits, Lucey said

"I ask many of my patients,'How is your sleep?'" said co-senior author Professor Beau M.

"Sleep and longitudinal cognitive performance in preclinical and early symptomatic Alzheimer disease" 20 October 2021, Brain