Why all-nighters do not work, and how sleep deprivation affects your psychological and physical health

Written by Varvara Dyakonova

The final exam season has begun for many and is fast approaching for others. And with all the stress and rushing to review and memorize a lot of information, the choice of pulling off an all-nighter might arise. All-nighters are marathons of studying when people stay up for several days. However, there are some risks associated with it and some difficulties. 

The medical term for the absence of sleep for more than 24 hours is sleep deprivation. It can range based on the awakening duration and can be described in terms of 24, 36, 48, 72, 96 and more hours of being without sleep. Although it might seem like the desired state when you are productive and can get many things done due to the prolonged wakening time, the psychological and physiological risks associated with this state are essential to mention. 

But let’s first discuss what sleep is and how it works from a physiological standpoint. The behavioural definition of sleep includes minimal movements, the lack of ability to describe the state you’re in, the lack of attention to the environment and relaxed posture. However, it is not enough to describe sleep from a cognitive or more scientific perspective. Thus, indirect neurophysiological measurements, such as EEG, EOG, and EMG, should be used. 

Scientists have discovered that brain activity differs in the types of waves or the pattern of neural excitement happening in the brain. Six distinct brain wave patterns can describe different stages of human activity. These brain patterns correspond to various activities humans perform, and the diagram below indicates the relative frequencies as well as actions performed during each type of wave.

 P.A.A. (2016). Brain wave samples with dominant frequencies belonging to beta, alpha, theta, and delta bands and gamma waves. [Graph]. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/brain-waves

Additionally, several neurotransmitters are involved, such as GABA, adenosine, nitric oxide and melanin. GABA is the primary inhibitory neurotransmitter involved in “shutting down” the activity of wake-promoting brain regions. Adenosine is a byproduct of brain metabolism, and when the levels are high, people start to feel sleepy. That’s why coffee is used as a minor stimulant, as it blocks the binding of adenosine to the receptors, and thus, a human starts feeling more alert and less tired. Nitric oxide is tied to the production of adenosine and acts as a signal to increase production. Melanin, famous for various supplements available for sleep-enhancing, is a regulator of the internal clocks by reacting to the dark environment. 

Two distinct theories can describe the reasons why we sleep. The first is the homeostatic theory, which states that humans and other animals need sleep for recovery to keep up with health and reestablish homeostasis. Homeostasis is the maintenance of relatively constant conditions in the body, despite the variability of external conditions. Examples of homeostasis can be body temperature, salt balance, pH levels and others.  However, this theory is difficult to test and to do so we need to find people who do not restart and without any recovery with altered homeostasis. People with sleep disorders are under stress conditions (cofounding variable). Is it stress or sleep deprivation? Philosophical assumptions can frame the definition of stress and explain how stress is a particular case of distorted homeostasis. These assumptions refer to external conditions that put external adaptive pressure on an organism.

The second theory is the adaptive theory of sleep, which states that different sleep schedules among living organisms are due to various environmental needs for adaptations. And these environmental factors affect sleep. 

Sleep is an important mechanism that helps achieve memory consolidation; during slow-wave sleep, declarative memory – knowledge, concepts, and meanings – is consolidated, while procedural memory, or how to perform some action, is consolidated during the REM sleep or rapid eye movement sleep, which happens about 90 minutes after a person falls asleep, and this is the stage in which people see dreams and most of the brain activities related to benefits of sleep happen during the REM sleep. 

So what happens with the brain and body when someone does not get enough sleep and is sleep-deprived?

While sleep deprivation can be divided into stages, such as sleep deprivation for 24, 36, 48, 72, or 96 hours or more, the symptoms increase in strength and severity with the prolongation of such state. They vary in severity from fatigue and irritability to anxiety, hallucinations, and distorted thinking and can cause sleep deprivation psychosis. Sleep deprivation psychosis includes hallucinations, such as visual, auditory and tactile hallucinations, and overall disconnection from reality,  Sleep deprivation has a severe effect on the brain. Firstly, the brain disposes of most of the waste during sleep, which happens by the lymphatic system, affecting the proneness of neurodegenerative diseases, such as Alzheimer’s. It takes longer sleep time for recovery, and statistically, just 1 hour of sleep takes four days to recover.

Additionally, sleep deprivation alters the neural connections in the prefrontal cortex and amygdala, which causes impairments in executive functioning, which refers to the mental processes of self-regulation, planning, decision making, attention and multitasking. These alterations cause increased moodiness and heightened emotional responses with hypersensitivity to rewarding stimuli. Additionally, there is an over-exertion of the prefrontal cortex, which causes impairments in alertness, thinking and concentration.  

The Brain – Diagram and Explanation. (2016). [Diagram]. Https://Www.Brainwaves.Com/

Therefore, sleep deprivation does not only affect the physiological state, causing hypertension, heart diseases and obesity but also causes changes in the neurological structure of the brain, altering consciousness and concentration. Consequently, there are changes in neurotransmitters, which are chemicals in the brain that act as messengers and signals for different functions, predominantly inhibitory, accountable for producing the feeling of sleepiness. Thusly, overproduction of adenosine causes the feeling of tiredness, and this feeling only builds up more as sleep deprivation prolongs. Therefore, creating an imbalance in the chemical content of the brain. However, due to neuroplasticity or the ability of the brain to modify, adapt and change in response to life experiences,  and homeostatic properties of the brain, sleep deprivation can be treated with sleep.

Overall, being awake for several days might seem like an attractive option, especially when there are so many things to do. Still, the abilities of the brain to memorize and recall information and the opportunity to think clearly decreases with the prolongation of being awake. Additionally, if you learn all the information, the cost outweighs the benefits, and you can start developing diseases and suffering from long-term consequences, especially as you get older. Even though everyone is telling us that sleep is essential, it is crucial to understand all the risks and make an informed decision of valuing your physical and mental health over some exams. You have only one body and one mind while having countless tests that, in the long term, will matter a lot less rather than your state. 

Tips and tricks

I know how stressing it might be to study for the exams, and I have laid down a couple of tips and tricks on how to improve your study habits without using all-nighters: 

  1. Use the technique of the 2-3-5-7 revision rule. 

This strategy indicates the revision schedule for any upcoming exam. Firstly, mark the day of the exam, then the day before would be the full review day. Then, count two days earlier from that day, this will be an additional review day. Then count back 3 days, 5 days and 7 days and those would be the days for review for the upcoming exam.

  1. Use a mind map to see all the topics being covered on an upcoming exam. 

It can be very overwhelming to cover a whole year or a whole semester’s worth of material right before the exam, but writing down what topics are needed to be studied, as well as marking ones that you are familiar with can take off the pressure and help to create a study plan suitable for your own needs.

  1. Use retrieval practices to test how well you can recall the information. 

This includes the usage of flashcards, doing practice tests, and making and answering questions. The usage of active recall improves the neural connections used to retrieve this information and helps to extract information better during exams.

  1. Understand the format of the upcoming exam. 

Exams are different, and they can include multiple-choice, filling the blanks, true/false statements, short answers and long answers. Those evaluation methods involve different skill sets that you can use to your advantage. If the exam is all long answers, then most likely it will include describing and providing arguments for some major topic in the course, whereas multiple-choice questions can be done with the process of elimination. Try to create a sample final exam for yourself and realize how the material can be tested to help prepare better.

  1. Study with friends

This way you can ask each other questions and explain difficult topics, which helps to better consolidate information and involves active recall and understanding of the material rather then memorization. Additionally, you can take turns explaining one concept at a time, while other people are asking questions and testing the knowledge of the orator. 

  1. Do a lot of practice questions

Usually, exams test the understanding and application part of the topics, rather than simple recall and factual knowledge, especially in technical subjects, such as math, chemistry, physics or biology. Do a lot of practice questions as it will help to learn strategies for solving different problems as well as understand the application of theories and equations.

  1. Take care of your physical and mental health

Exams are stressful, but taking care of yourself should be the primal focus of any human being. Going for a walk, taking breaks, eating healthy and having a proper sleep schedule help to improve the mental state, decrease stress as well as keep the brain in the best possible state to actively work during the exam season. One of the professors at my university has told everyone: “You can easily recover from a low grade, but being admitted to a hospital due to a nervous breakdown or overwork will leave permanent damage to both your health and your current studies”. So please take care of yourself, a grade is just a number and it does not reflect who you are as a person, your intelligence or your self-worth.


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