Rapid eye movement (REM) sleep is the stage of sleep when we dream. It was first described by Eugene Aserinsky and Nathaniel Kleitman in a 1953 Science article.

Decades later, we still have a lot to learn about this phase of sleep.

One concern researchers have is that REM sleep deprivation may harm human health. You may not be getting enough REM sleep if:

  • You take antidepressant medications
  • You have a sleep disorder

This article looks at REM sleep deprivation and how it might affect memory and learning.

What Is REM Sleep?

REM sleep is one of the two major natural sleep stages. It is so distinct that other stages are sometimes grouped together as “non-REM sleep.”

Modern sleep studies like polysomnogram use different tools to measure sleep activity. These include:

  • Electroencephalogram (EEG) to measure brain waves
  • Electromyogram (EMG) to measure muscle activity
  • Electrooculogram (EOG) to measure eye movement

The brain is active during REM sleep. Most muscles are not. 

Most skeletal muscles, except those used for eye movement and breathing, are paralyzed during this phase of sleep. Skeletal muscles are the muscles that control voluntary movements like walking.

Vivid dreams are another core part of REM sleep. Paralysis may prevent you from acting out your dreams.

Without this paralysis, REM sleep behavior disorder can happen. People with this condition act out their dreams during sleep.

Important Functions of REM Sleep

Research is not conclusive, but it suggests that REM sleep is important for daytime function. It may help you learn and consolidate your memories.

Recap

REM sleep is the sleep stage associated with dreaming. During REM sleep, your muscles relax and your brain becomes active. 

REM sleep is thought to be helpful for procedural memory. This is the type of memory you use when you learn a new skill, like how to ride a bike. It differs from factual or semantic memory. This is the type of memory you use for something like dates or lists of facts.

REM sleep may also help you solve problems. During REM sleep, you may make unique connections within your brain. 

During REM sleep, you have vivid dreams. They may unfold like a movie in which you are an actor. When the content of a dream is disturbing, you may experience it as a nightmare.

Mood disorders can change the experience of dreams. This could happen for people with:

  • Anxiety
  • Depression
  • Post-traumatic stress disorder (PTSD)

Causes of Dream Deprivation

Sleep deprivation has real impacts on health and well-being. The most obvious is sleepiness. Feeling sleepy can affect your work and family life. It can also make it dangerous to do things like drive a car.

REM sleep may be important for memory and daytime function. It may also help you learn new skills.

Sleep deprivation also affects things like:

  • MetabolismPainHeart health

Sleep has structure. REM sleep happens at regular intervals during the sleep period. This is typically every 90 to 120 minutes.

REM sleep may last 5 to 30 minutes. The periods of REM sleep usually become longer towards morning. This means most REM sleep happens in the last one-third of the night. When you wake, the last period of REM sleep may be interrupted.

If your REM sleep is often disturbed, you may have false awakenings. This is when you feel like you woke up but are actually still dreaming. 

In some situations, you may spend less or no time in REM sleep. If you don’t get enough total hours of sleep, for example, that can lead to less REM sleep overall.

You may also spend a greater percentage of the night in REM sleep. This happens because you may not spend any time in lighter sleep. This is part of the sleep consolidation process, when you’re “catching up” on lost sleep.

Substance use has a strong impact on REM sleep. The following are known to suppress REM sleep:

  • Caffeine
  • Alcohol
  • Marijuana
  • Opioid or narcotic pain medications
  • Benzodiazepine medications
  • Antidepressant medications
  • Lithobid (lithium)

Sleep disorders may also cause fragmented REM sleep. This is especially true for:

  • Obstructive sleep apnea
  • Narcolepsy

During REM, the muscles relax. This may cause airway muscles to collapse. When this happens, it can trigger the breathing disturbances of sleep apnea. This can interrupt REM sleep.

Sleep apnea can be treated with continuous positive airway pressure (CPAP) therapy. This is a device that keeps the airway open during sleep. Effective sleep apnea treatment can help REM sleep rebound.

Unclear Effects of Dream Deprivation

Alcohol and antidepressants are widely used. Sleep apnea is very common. Still, research has not been able to show that the sleep deprivation caused by these things has a strong impact on health.

You may experience dream deprivation if you use certain substances like alcohol and antidepressants. Sleep disorders like narcolepsy and sleep apnea can also cause you to lose REM sleep.

Even in patients who have used antidepressants for decades, there does not seem to be any measurable health impact caused by long-term sleep deprivation.

Subjects with permanent damage to the REM-related part of the brain can seem unaffected by the loss of REM sleep. These subjects may have normal memory and no loss of function. The purpose of REM sleep is still unknown.

Summary

Rapid eye movement sleep is the sleep stage associated with dreaming. During this stage, your brain is active and your muscles are relaxed.

The science is unclear about the long term effects of dream deprivation. More research is needed.

Scientists don’t yet understand why we need REM sleep. It may be important for memory and daytime function.

Many factors can influence how much REM sleep you get. Substance use and sleep disorders like sleep apnea can all have an effect.

The long-term effects of dream deprivation are unknown. Still, sleep in general is important to health and well-being. 

A Word From Verywell

If you’re worried about REM sleep deprivation, contact a board-certified sleep physician. Ask about the benefits of a diagnostic sleep study.

More research is needed into the effects of REM sleep deprivation. Still, getting a good night’s sleep will always help you feel your best.

Frequently Asked Questions

  • What are the signs of REM sleep deprivation?
  • Clues you may not be getting enough sleep in general and therefore are missing out on REM sleep include:Falling asleep quickly, as soon as a few minutes after your head hits the pillowDaytime drowsinessMicrosleeping, or nodding off during the day
  • What happens to the body during REM sleep?
  • REM sleep is characterized by distinct biological changes:Skeletal muscles relax to the point of paralysisBreathing speeds upHeart rate increasesBlood pressure risesThe eyes, although closed, move rapidly beneath the lidsMales have erectionsBody temperature falls to the lowest point of the day or night
  • Why do we dream during REM sleep?
  • Some experts believe changes in brain wave activity paired with an increase in the firing of nerve cells (neurons) in the brain during REM sleep contribute to dreaming.

Clues you may not be getting enough sleep in general and therefore are missing out on REM sleep include:

REM sleep is characterized by distinct biological changes:

Some experts believe changes in brain wave activity paired with an increase in the firing of nerve cells (neurons) in the brain during REM sleep contribute to dreaming.