Why do we Sleep ?

Sleep is one of the vital functions of the body.1 It has been a mystery for the researchers and thinkers alike for thousands of years to understand the need and the structure of sleep.

More recently, studies trying to understand the sleep physiology or how it happens has gained momentum. As recently as 2017, the Nobel Prize ( Physiology and Medicine)  was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young for their discoveries of molecular mechanisms controlling the circadian rhythm.2

Their discovery of the per(Period) gene and later tim(time) gene and the cyclical nature of the gene and its protein modulation creating a circadian rhythm to guide the fruit fly ( that represents animal kingdom) in terms of sleep was a landmark breakthrough in the field of science. That also emphasized that similar mechanisms are occurring across the various life forms and sleep is genetically encoded. So even though the purpose is still elusive, understanding the function of sleep is still something we can demystify by understanding the effects of sleep deprivation.

Let me give a small mental exercise at this point of time.

Just try to remember a day in your past when you were unable to sleep overnight and the consequences on the next day.

You would realise, you were probably not your best the next day. Sleep deprivation of even a single day can create havoc and we are unable to focus properly, become more irritable, feel tired through the day till our sleep deprivation gets a little better by sleep at the next permissible time and place.

Sleep deprivation over a prolonged period of time has been shown to be associated with multiple effects on the mental, cognitive, emotional and physical health of a person.

Cognitively (related to mental function) sleep deprivation impairs attention and working memory, long-term memory and decision-making. Even partial sleep deprivation of sleep a few hours less over a long period of time is also associated with decreased attention and alertness.3

Depression and its relation with circadian rhythm ( the cyclical 24 hour sleep and wakefulness biological loop ) has been extensively studied and it has been found that both lead to each other ( Depression would not let you sleep and sleep deprivation would lead to depression) and people who are chronically sleep deprived are more at risk for depression and negative thinking.4

At a more physical level, people with chronic sleep deprivation face metabolic consequences like insulin resistance leading to Diabetes, refractory hypertension, Hypercholesterolemia, endothelial dysfunction leading increased mortality and morbidity in that subgroup of the population.5

This much understanding also alerts us to the essential nature of sleep and its effects on our body and mind. We might still want to work more into the night but we will still need to catch up on our sleep for our optimal functioning.

Author : Dr Sweta Singla

Sr. Consultant Neurology & Sleep

MD, DM Neurology


References :

  1. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep

  2. https://www.nobelprize.org/prizes/medicine/2017/press-release/

  3. Alhola P, Polo-Kantola P. Sleep deprivation: Impact on cognitive performance. Neuropsychiatr Dis Treat. 2007;3(5):553‐567.

  4. Wiebe ST, Cassoff J, Gruber R. Sleep patterns and the risk for unipolar depression: a review. Nat Sci Sleep. 2012;4:63‐71. Published 2012 May 29. doi:10.2147/NSS.S23490

  5. Worley SL. The Extraordinary Importance of Sleep: The Detrimental Effects of Inadequate Sleep on Health and Public Safety Drive an Explosion of Sleep Research. P T. 2018;43(12):758‐763.


©2020 by knolead.com. Proudly created with Wix.com