Do You Sleep Better When You Dream? (Research Summary)

In general, dreaming does result in better sleep quality.

However, there are exceptions.

It’s also possible to dream while tossing and turning all night and wake up barely feeling rested.

What’s the deal?

I’ve read through several studies relevant to this topic in order to get an answer. I’ll summarize the most important points in this post.

When Do You Dream?: The REM Sleep Cycle

Let’s quickly go over the basics.

There are 4-5 stages of sleep depending on who you ask (1).

While it is possible to dream at all stages of sleep, vivid dreams occur during REM (rapid eye movement) sleep, which occurs at the end of each 90-110 minute sleep cycle. This is also the stage that insomnia typically occurs because it's the lightest.

One key note is that the length of each stage during each cycle changes over the course of the night.

REM sleep is short during the first cycle (just a few minutes usually), but gets progressively longer each cycle.

SummaryVivid dreams occur during the REM cycle of sleep. If you’re sleep deprived, REM sleep is shortened and delayed (it’s the lowest priority).

What Happens While You’re Dreaming

While you’re dreaming, there are both physiological and neurological changes compared to other stages of sleep.

You have rapid eye movements (hence the name REM), and your muscles relax almost completely (2).

Image from the University of Michigan’s online course on the biology of sleep.

Additionally, your overall brain activity during REM is similar to when you're awake, just in slightly different parts of the brain (3). For example, decision making is impaired during REM sleep (which is why we do strange things in dreams sometimes).

Research suggests that dreams are derived from memories, thoughts, and wishes that you have (4).

SummaryThe brain gets a lot more active during dreams than other parts of sleep.

Why Do We Dream?

No one still knows for sure, and researchers have different theories.

Some of them are more backed up by science than others. Here are the most probably theories from what I’ve seen:

• For learning - If you sleep (a period that includes REM sleep) after learning a new task, you’ll be better at it compared to if you hadn’t slept (5).
• For memory - Regional brain activity during REM sleep is linked to areas involved in memory (6).
• For health - While the mechanism is unclear, it’s been shown that a lack of REM sleep leads to higher levels of inflammation (and worse immune function) (7).

There are also theories that dreaming helps us deal with emotional issues, but that’s a really tough thing to study.

How Your Dreams Affect Your Sleep

Now we can really start looking at whether or not you sleep better when you dream.

It’s clear that dreaming is required for high quality sleep, but does dreaming automatically mean that your sleep is good?

As it turns out, no it doesn’t.

A study looked at the effect of nightmares on sleep quality and found (8):

Our results suggest that nightmare disorder causes waking distress, negative mood, non-restorative sleep and tiredness during the day.

What’s interesting is that nightmares don’t change the structure of your sleep (i.e. duration of sleep at each stage, number of wake ups, etc.), only the quality.

SummaryStressful or scary dreams result in lower quality sleep. So while dreaming is needed for high quality sleep, the type of dream matters also.

How Long Do You Dream For?

If you remember the diagram of sleep cycles from before, REM sleep only occurs for a few minutes at the end of the first cycle.

If you sleep for a full night (8+ hours), the final REM duration can be 30 minutes or more.

Each of these periods is a separate “dream,” and it’s common to be able to remember your 2-3 longest dreams of the night.

Side Effects of Not Getting Enough REM Sleep (and Dreaming)

We looked briefly at the benefits of REM sleep, now let’s look at the consequences of not getting enough, which happens if you’re sleep deprived:

• Weight gain - Short sleep duration is strongly correlated to being overweight, and research suggests that a lack of REM sleep is likely a main factor (9).
• Inflammation - Depriving sleep study subjects of REM sleep (but letting them sleep in other stages) resulted in increased inflammation, which affects immune function (10).
• Increased pain sensitivity - Losing just a few hours of sleep, and specifically the REM periods results in increased pain sensitivity the following day (11).

There are likely many other smaller side effects that are still being uncovered.

The specifics don’t matter all that much, as long as you understand that it’s important for a variety of reasons.

How To Dream Better (i.e. Get More REM Sleep)

Unless you have insomnia, the biggest factor in sleep quality and duration is sleep hygiene.

Good sleep hygiene includes (among others):

• Avoiding alcohol and cannabis
• Limiting light exposure at night (particularly blue light)
• Avoiding unnecessary medicine that may cause sleep issues
• Having a sleep schedule
• Dealing with stress before going to sleep (the best you can)

Another way to aid sleep is with time-released melatonin supplementation.

It’s available over the counter in North America and many other countries, and generally safe to use if you follow the instructions. Just 0.3-1.0 mg of melatonin is usually enough to get the majority of the benefits (12).

References

1. Mechanisms of Association of Sleep and Metabolic Syndrome
2. Muscle tone regulation during REM sleep: Neural Circuitry and Clinical Significance
3. Hemispheric lateralization of the EEG during wakefulness and REM sleep in young healthy adults
4. Dreaming and the brain: from phenomenology to neurophysiology
5. Dreaming and offline memory processing
6. Dreaming and Waking Cognition
7. Dreamless: the silent epidemic of REM sleep loss
8. Nightmares affect the experience of sleep quality but not sleep architecture: an ambulatory polysomnographic study
9. Rapid Eye Movement Sleep in Relation to Overweight in Children and Adolescents
10. Immune alterations after selective rapid eye movement or total sleep deprivation in healthy male volunteers
11. Sleep loss and REM sleep loss are hyperalgesic
12. Melatonin in Patients with Reduced REM Sleep Duration: Two Randomized Controlled Trials