Written by: Kirsten Yip
Introduction
Sleep is universally included in all of our unique daily routines. After all, it’s as essential to human survival as food and water. However, in today’s rapidly moving and hyper-productive society, it might be considered low priority amongst other tasks. We push bedtimes later, set alarm clocks earlier, and conquer the days with coffee, yawns, and 10-minute naps. As a result, sleep deprivation is not uncommon, with 20% of the adult population reporting sleep deprivation (1) and 70% of the post-secondary student population reporting insufficient sleep (2). Thus, getting inadequate sleep shouldn’t be so easily chalked up to the normal fatigue of a hustling and bustling lifestyle.
What is Sleep Deprivation?
Sleep deprivation occurs when insufficient sleep leads to slowed alertness, decreased performance, and deterioration in health (3). Sleep is typically defined as a reversible state of reduced responsiveness, motor activity, and metabolism (1). Two primary processes regulate how much sleep is obtained: the homeostatic sleep drive and the circadian rhythm (2). The homeostatic sleep drive increases the need for sleep as the day goes on and the period of wakefulness gets longer and longer. The circadian system is an internal clock within our bodies that helps regulate sleep/wake cycles and hormonal secretions (2). While the biological purpose of sleep remains a scientific mystery, we do know that it’s essential. This dynamic process impacts almost every system in the body; it helps restore energy, strengthens our immune system to fight off illness, helps us think more clearly and creatively, strengthens memory, and produces a more positive mood for better performance (4).
Insufficient sleep is caused by decreased quantity or quality of sleep. A decrease in quantity of sleep occurs over multiple nights and if it happens regularly, loss of sleep results in an unrecoverable sleep debt (1). But contrary to popular belief, it’s not only about getting enough hours of sleep. According to the Centers for Disease Control and Prevention (CDC), adults ages 18 to 60 years old need to be getting seven or more hours of sleep every night (5). However, even if a person sleeps more than 7 hours nightly, sleep deprivation can still occur due to a poor sleep quality, which is determined by the number of awakenings from sleep throughout the night (1). This idea is similar to how you can consume a bunch of snacks throughout the day, effectively eating a lot, but the quality and nutrition here doesn’t beat having 3 solid meals; quality and quantity both matter!
The Effects of Sleep Deprivation
Well... if so many people are able to function while sleep deprived, what’s the harm for you? It’s unclear why some individuals are more or less vulnerable to sleep deprivation (6). However, it does eventually take an effect on everyone. While our bodies might be able to operate on decreased quantity and/or quality of sleep, they are not operating efficiently. Sleep deprivation presents itself subtly in our daily lives through signs; this includes having trouble with concentration and memory, greater emotional reactivity, and lower motor performance (6). Although these are the overall measurable impacts, there is so much more going on within the brain.
The micro-details of sleep deprivation are still under exploration as it is a complex phenomenon that’s difficult to ethically study. In short, we know that being sleep deprived impairs your cognitive performance (7). Neuroimaging evidence identifies two areas of the brain that are particularly vulnerable to sleep loss: the prefrontal cortex and the parietal lobe (3,7). These two areas are significantly involved in attention, working memory, learning, self-control and emotion and dopamine function (6).
Image Description: MRI and hand-drawn sketch of the brain showing the locations of the prefrontal cortex and the parietal lobe. Image Adapted from Sean Novak. (8)
For students, the basic idea is that sleep deprivation leads to impaired activity within the aforementioned areas of the brain. This can in turn result in increased risk of academic failure, compromised learning, impaired mood, increased mental health issues, decreased performance in physical activities and athletics, and increased risk of motor vehicle accidents (2,4).
Physical Health Implications
It’s also important to consider that chronic sleep deprivation can have physical health implications, including but not limited to (9):
Obesity – due to increased production of ghrelin and limited production of leptin. These are two hormones that majorly influence energy and hunger balance. Ghrelin is known as the “hunger hormone” whereas leptin suppresses food intake (10).
Permanent cognitive effects
Mental status changes resembling depression or anxiety
Increase in mortality
What causes sleep deprivation?
There are many reasons why an individual might end up sleep deprived. This can include voluntary behaviour, such as consuming alcohol, caffeine, stimulants and technology. As well, non-voluntary behaviour; for instance, personal obligations, work obligations or medical problems. Students seem to be particularly susceptible to becoming sleep deprived. The university experience provides an environment where students can gain knowledge, skills, and independence. This is quite an exciting time period; however, as students chase academic achievement, self-growth, and social interaction, stress and long to-do lists easily provoke sleep deprivation.
Scientists have found that university students are not even aware of the extent to which sleep deprivation negatively affects their ability to complete cognitive tasks (7,11). It’s important to acknowledge if you’re feeling sleep deprived because it can be cured! Good sleep hygiene must be practiced and sleep habits must be permanently restructured. In other words, an individual must make lifestyle changes to obtain enough good quality sleep.
Easy changes to implement into your night routine to optimize sleep:
Have a regular sleep-wake schedule, with a routine
Sleep in a quiet environment
Avoid caffeine and nicotine late in the day
Exercise 20-30 minutes a day, but avoid these stimulating activities in the couple of hours before bed
Unplug before bed – remove televisions, personal electronic devices, and other blue-light distractions from the bedroom; learn more about the effects of blue light in next week’s blog post!
While this proves to be a difficult task, it’s essential to getting a restful sleep. Scientific data correlates electronically-emitted light with promoting wakefulness and alertness. This is because the circadian system is super sensitive to the short-wavelength (blue) light (12). Delaying this circadian clock means that alertness is increased immediately before bedtime and melatonin levels are suppressed, causing it to take longer to fall asleep (13).
Sleep deprivation is often glamorized in academic culture and on social media. Getting a proper night’s sleep, however, should remain one of our top daily priorities. Going to sleep is not being lazy! Those who are more inclined to give up sleep the night before that final exam are actually putting themselves at the disadvantage.
References
Abrams RM. Sleep Deprivation. Obstet Gynecol Clin North Am. 2015 Sep;42(3):493–506.
Hershner S, Chervin R. Causes and consequences of sleepiness among college students. Nat Sci Sleep. 2014 Jun;73.
Killgore WDS. Effects of sleep deprivation on cognition. In: Progress in Brain Research [Internet]. Elsevier; 2010 [cited 2020 Nov 16]. p. 105–29. Available from: https://linkinghub.elsevier.com/retrieve/pii/B9780444537027000075
University Health Center, University of Georgia. Sleep Rocks! ... Get More of It!
Are You Getting Enough Sleep? [Internet]. National Center for Chronic Disease Prevention and Health Promotion, Division of Population Health; 2020 Mar. Available from: https://www.cdc.gov/sleep/features/getting-enough-sleep.html
Krause AJ, Simon EB, Mander BA, Greer SM, Saletin JM, Goldstein-Piekarski AN, et al. The sleep-deprived human brain. Nat Rev Neurosci. 2017 Jul;18(7):404–18.
Goel N, Rao H, Durmer J, Dinges D. Neurocognitive Consequences of Sleep Deprivation. Semin Neurol. 2009 Sep;29(04):320–39.
Novak S. Brain T2 axial [Internet]. Wikimedia Commons. 15AD [cited 2020]. Available from: https://commons.wikimedia.org/wiki/File:Brain-T2-axial.png
Institute of Medicine (US) Committee on Sleep Medicine and Research. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem [Internet]. Colten H, Altevogt B, editors. Washington, DC: National Academies Press (US); 2006. Available from: https://www-ncbi-nlm-nih-gov.libaccess.lib.mcmaster.ca/books/NBK19961/
Klok MD, Jakobsdottir S, Drent ML. The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review. Obes Rev. 2007 Jan;8(1):21–34.
Pilcher JJ, Walters AS. How Sleep Deprivation Affects Psychological Variables Related to College Students’ Cognitive Performance. J Am Coll Health. 1997 Nov;46(3):121–6.
Figueiro MG, Bierman A, Plitnick B, Rea MS. Preliminary evidence that both blue and red light can induce alertness at night. BMC Neurosci. 2009 Dec;10(1):105.
Chang A-M, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci. 2015 Jan 27;112(4):1232–7.
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