Restful Nights and Healthy Minds: Unraveling the Connection between Sleep and Dementia
Writer: Vijaya Varadarajan
Editor: Brianna Viets, and Prahalad Srinivasan
Your heartbeat slows down, your thoughts center to nothingness, and your eyelids meet each other to portray a black emptiness of nothing… or is it everything? A considerate inhalation and one final exhalation before you’re plunged into a labyrinth of vivid and newfound subconscious memories: sleep.
What exactly is sleep?
Sleep is the harmonious piecing of various parts of the brain, orchestrating one of life's most important processes. The hypothalamus consists of the suprachiasmatic nucleus (SCN), which is a group of numerous cells that receive information about light exposure from the eyes to accordingly direct your behavioral rhythm. The brain stem along with the hypothalamus contains GABA (a brain chemical), which is crucial in reducing activity in arousal centers. The brain stem also sends signals to relax muscles to initiate REM sleep. What is REM sleep? Well, it is a stage of sleep called Rapid Eye Movement Sleep. As the name suggests, the eyes of a sleeper move rapidly but don’t process any visual information. This stage occurs 90 minutes after the onset of sleep and is crucial in stimulating parts of the brain for memory and the production of vital proteins. The thalamus tunes out the external noise, leaving you alone, deep in the healing powers of sleep. Lastly, the amygdala plays its part in interpreting emotions (“Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and Stroke”).

Figure 1: Anatomy of the Brain from “Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and Stroke”
Sleep and Dementia
It is needless to say sleep is the most effective, nature-made solution to all problems. Well, perhaps most problems. According to research published in the National Library of Medicine, sleep regulates metabolism, decreases mental fatigue, and most importantly, enhances memory recall (Eugene and Masiak). Conversely, around 50 to 70 million Americans suffer from chronic or progressing sleep disorders (“What Are Sleep Deprivation and Deficiency?”). Science suggests that there is a clear and well-defined relationship between not acquiring enough sleep and dementia. The American Journal and Preventive Disease, states that about 44% of patients with Alzheimer’s Disease have sleep disorders, this percentage rises to 90% with patients suffering from Dementia. (“Sleep Disturbances and Dementia Risk in Older Adults: Findings From 10 Years of National U.S. Prospective Data”)
What happens to the brain during sleep deprivation?
Sleep deprivation increases the production of beta-amyloid- and as our blog on taking the journey through the scientific intricacies of Alzheimer’s within the brain states, beta-amyloid builds up as plaque, impeding the movement of electrical impulses in the brain. Along with this, sleep fragmentation, and repeated short interruptions of sleep, can impact the APOEε4 gene. This gene is the most prevalent risk factor for Alzheimer’s Disease. The lack of sleep can also affect the permeability of blood into the brain and oxidative stress (oxidative stress occurs when the body’s antioxidant levels are low). (“Sleep Disturbances and Dementia Risk in Older Adults: Findings From 10 Years of National U.S. Prospective Data”)

Figure 2: Points out the everlasting cycle of sleep deprivation and its contribution to Alzheimer’s Disease. This image is from Psychology Today (Charvat).
In summary, this mesmerizing link between sleep and dementia allows us to appreciate our bodies' need to rest. Whether it be to enrich humankind’s most basic cognitive function or to delve deep into the unconscious recollections of thought, sleep (for any time between 7-9 hours) is a step one must take to prioritize cognitive well-being. So I must ask you, did you sleep well last night?

Figure 3 from (“Sleep and mental health”)
Works Cited
“Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and Stroke.” National Institute of Neurological Disorders and Stroke, 19 July 2023, https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep. Accessed 4 December 2023.
Bryant, Erin. “Lack of sleep in middle age may increase dementia risk.” National Institutes of Health (NIH), 27 April 2021, https://www.nih.gov/news-events/nih-research-matters/lack-sleep-middle-age-may-increase-dementia-risk. Accessed 4 December 2023.
Charvat, Mylea. “Can Sleep Deprivation Cause Alzheimer's?” Psychology Today, 15 July 2019, https://www.psychologytoday.com/us/blog/the-fifth-vital-sign/201907/can-sleep-deprivation-cause-alzheimer-s. Accessed 4 December 2023.
Eugene, Andy R., and Jolanta Masiak. “The Neuroprotective Aspects of Sleep.” National Library of Medicine, National Library of Medicine, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651462/.
“Sleep and mental health.” Beyond Blue, https://www.beyondblue.org.au/mental-health/sleep. Accessed 4 December 2023.
“Sleep Disturbances and Dementia Risk in Older Adults: Findings From 10 Years of National U.S. Prospective Data.” American Journal of Preventive Medicine, AJPM, https://www.ajpmonline.org/article/S0749-3797(23)00009-0/fulltext#:~:text=Is%20sleep%20 disruption%20a%20risk%20 factor%20 for%20 Alzheimer's%20disease%3F.&text=UP%20to%2044%25%20 of%20 patients,bodies%20or%20 Parkinson%20disease%20 dementia.
“What Are Sleep Deprivation and Deficiency?” National Heart, Lung, and Blood Institute, National Heart, Lung, and Blood Institute, https://www.nhlbi.nih.gov/health/sleep-deprivation.
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