You may realize that you don’t feel like your mind is working at 100% capacity when you have not gotten a full night’s sleep, but did you know that sleep disorders can actually cause dementia and cognitive decline? Recent observational studies indicate that individuals who are not getting a full, restful night’s sleep are more prone to diseases of the brain such as Alzheimer’s Disease, as well as other cognition problems. Turns out hitting that snooze alarm one more time may be your brain’s way of letting you know that you need more (and better quality!) rest.
Benefits of Restful Sleep
A full, restful night’s sleep is defined as anywhere between 6-9 hours depending on the individual, but sleeping longer does not necessarily mean you are sleeping better. Sleep quality is also a big concern with Americans today; the use of medications to alter sleep habits is on the rise. Around 4% of U.S. adults aged 20 and over are using sleep aids on a regular basis and up to 7% of older adults. Sleep plays an important role in memory and health, as well as our overall learning capacity as humans. Sleep is regulated in the body much in the same way that hunger and thirst are regulated, suggesting that sleep is another of our body’s critical functions to maintain health.
Types of Sleep Disorders
One of the most well-known sleep disorders is insomnia, which occurs when individuals have difficulty falling asleep, staying asleep and may have poor sleep quality or duration. A secondary grouping of sleep disorders are considered sleep related breathing disorders, or sleep apnea, and includes snoring, Upper Airway Resistance Syndrome (UARS), Obstructive Sleep Apnea (OSA) and Central Sleep Apnea (CSA). Circadian Rhythm Disorders, also known as shift work disorder, occur when your body feels out of phase with the cycles of day and night, which can cause insomnia or hypersomnia (excessive sleepiness) at odd hours of the day or night. Restless leg syndrome, where the nerves in your legs are unable to take a break for the night, can also cause a poor night’s sleep.
Links between Poor Sleep and Cognitive Disorders
Recent studies with self-reporting (questionnaires) and using objective sleep measures (wrist actigraphy) show that the links between cognitive disorders and low quality sleep are not yet clear; however, it is thought that poor sleep quality is linked to many pivotal changes in your body, such as lower cerebrospinal fluid levels, inflammation, change in immune modulation (both peripherally and centrally), and even altered metabolism in the brain. It has definitely been linked to poor memory consolidation and difficulty forming long term memories. Sleep-disordered breathing may decrease the clearance of amyloid beta, which is an aberrant protein strongly associated with Alzheimer’s disease, from the brain.These changes can be highly detrimental to the neurons, neural connections, and ultimately, memory cognition and overall brain health.
While there is still much work to be done to concretely tie cognitive disorders to essential sleep patterns, the current work being done in the field is impressive enough to suggest that getting into a regular habit of healthy sleep may help ward off dementia, or at least significantly slow its advance.