Sleep Drive

Sleep/wake homeostatis

Sleep is regulated by two body systems: sleep/wake homeostasis and the circadian biological clock. Homeostatic influences preserve the balance between sleep and waking so that a change in one results in a compensatory change in the other. This means that the longer you stay awake, the sleepier you become.

When you have been awake for a long time, sleep/wake homeostasis tells you that need to sleep. It also helps you maintain enough sleep throughout the night to make up for the hours of being awake. If this restorative process existed alone, it would mean that you would be most alert as your day was starting out and that the longer you were awake, the more you would feel like sleeping. In this way, sleep/wake homeostasis creates a drive that balances sleep and wakefulness.

Sleep Drive and Circadian Rhythm

The circadian rhythm causes you to feel alert even if you have been awake for hours but your sleep drive makes you feel sleepy. The sleepiness you experience during circadian dips will be less intense if you have had sufficient sleep, and more intense when you are sleep deprived.

Sleep drive increases the longer you stay awake. If the sleep drive is not relieved, sleepiness worsens. If the duration of sleeplessness is prolonged, cognitive and behavioral functions may be impaired.

Longer sleep then ultimately results, in keeping with theories of sleep’s restorative purpose. As your body recovers, your sleep drive is reduced. In the end, it is vital to keep a regular sleep schedule and to allow plenty of time for quality sleep. This will allow sleep drive and circadian rhythm to help you perform at your best.

Sources:

• Henry G. Raroque, MD. (2014). Lecture notes on Introduction to Sleep. The Dallas School of Neuroscience and Sleep Medicine, Texas.

• Monk TH, Welsh DK. (2003). The role of chronobiology in sleep disorders medicine. Sleep Med Rev. Vol 7, pages 455-473.
• Van Dongen HP, Maislin G, Mullington JM, Dinges DF. (2003). The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep. Vol 26, pages 17-126.
• org by National Sleep Foundation, Maryland. Sleep Drive and Your Body Clock. Retrieved on March 2018 at https://sleepfoundation.org/sleep-topics/sleep-drive-and-your-body-clock