Despite the fact that everyone dreams (though we don’t always remember our dreams when we wake up), scientists still aren’t entirely sure why we dream. Freud famously believed dreams were an expression of things we repressed during our waking hours, but current-day psychologists are split over whether dreams have any deeper meaning or are simply the result of random brain activity that happens while we’re unconscious.
The debate rages on. In the current issue of The New Yorker, writer Zoe Heller reviews the new book Why We Dream, by Alice Robb, in which the author makes a spirited case for dreams as “another realm of being, a second consciousness, rich in adventure and wisdom.” Robb is quick to acknowledge that dream interpretation has its limits—that “the line between mystic garbage and truth can be blurry”—but she knows that dreams have power, even if science can’t prove it.
Here’s what we do know about dreams: There’s ample evidence that rapid eye movement (REM) sleep, the stage when most dreaming takes place, is essential to our mental and emotional well-being. Research suggests that dreaming can help us sort through feelings and even prepare our minds to cope with threatening situations in real life.
There are two core stages of sleep: deep sleep, which includes stages 1-4, and REM sleep. During REM sleep, the brain experiences a spike in activity—hence, dreaming. One enters REM sleep within the first 90 minutes of falling asleep and then cycles through it again and again over the course of the night. REM sleep accounts for up to one-fourth of an adult’s sleep cycle, and its duration increases as the night goes on.
What causes vivid dreams
In the course of writing her article for The New Yorker, Heller decided to keep a dream journal. “The results, it has to be said, have not been very exciting so far,” she writes. “I appear to spend an inordinate amount of my dream life on the subway or squabbling with ex-boyfriends.”
Other common (and more disturbing) dreams that many of us have include our teeth falling out, being naked in public, and feeling trapped. While science has yet to pinpoint the cause of those dreams—and whether or not they can tell us anything meaningful about our lives—they might have a surprisingly simple explanation.
Here are six common causes of uncommonly vivid dreams.
1. You’re taking a melatonin supplement
Melatonin is the hormone that regulates your circadian rhythm (i.e., your sleep-wake cycle). Melatonin sleep supplements are a popular treatment available OTC. The thing is, they’re often sold in high doses (1-3 milligrams) that can cause side effects, including crazy dreams.
A small study published in the journal Sleep and Hypnosis looked into the connection between melatonin supplements and crazy dreams. The researchers had 22 participants ages 18-25 with good sleep habits take either a 6-milligram dose of melatonin or a placebo every night for two weeks, then answer a questionnaire about their dreams in the morning.
The researchers hypothesized that the participants who took melatonin experienced more vivid dreams than those on the placebo because melatonin affects the quality and length of REM sleep. (Interestingly, the women participants noted more bizarre dreams than the men.)
If you want to take a melatonin supplement but would rather avoid crazy dreams, limit your dosage. Melatonin can be effective in as little as 0.1 to 0.3 milligrams.
2. You’re stressed—all the time
Stress is bad for you for a whole host of reasons: It can do everything from cause acid reflux to lead to depression to increase your risk of heart attack. Stress can also impact your dreams.
Research has shown that having negative thoughts before you hit the sheets can result in nightmares. A study published in the Journal of Sleep Research examined the stress-nightmares link. 147 participants kept a log of their dreams for two weeks, rating them for how pleasant or unpleasant they were. Those with anxiety, depression, and stress experienced more nightmares.
According to Psychology Today, nightmares are a normal reaction to stress—some experts even believe that nightmares help people work through traumatic experiences. Incorporating meditation and exercise into your daily routine are two easy ways to cut down on stress. (Learn about how stress and anxiety can cause maladaptive daydreams.)
3. You have a sleep disorder
According to the National Sleep Foundation, sleep apnea can cause crazy dreams. Sleep apnea messes with REM sleep, and this can lead to vivid dreams, in particular nightmares. Sleep apnea also cuts off your oxygen supply while you’re asleep, and this can also lead to an uptick in disturbing dreams.
In fact, people with sleep apnea often report reoccurring dreams of suffocating or drowning. In essence, these dreams are a manifestation of the fact that you’re not able to breathe while you sleep when you have sleep apnea.
Restless Legs Syndrome (RLS) and narcolepsy are two other sleep disorders that can cause crazy dreams, as they also both result in abnormal REM sleep.
If you think you have a sleep disorder, the best thing to do is head to a sleep doctor who can diagnose you and come up with a treatment plan. With sleep apnea, using a CPAP (continuous positive airway pressure) machine and sleeping on your side can help you get better sleep.
Treatments for RLS include taking iron supplements (iron deficiency is a common sign of this sleep disorder), exercising more, and massaging your legs, while narcolepsy is often treated with prescription medication.
4. You eat a lot of spicy food before bed
There isn’t any research proving that eating certain types of foods will result in crazy dreams, but anecdotally, many people say that noshing on spicy food makes them have dreams that are more bizarre than usual.
Researchers in Canada did a deep dive into this topic for a study published in the journal Frontiers in Psychology, interviewing 396 college students about how they believed food affected their dreams. 17% of participants said eating specific types of foods (cheese, milk, ice cream, spicy foods, and sweets were the most common) resulted in them having bizarre or disturbing dreams.
The researchers pointed out that this doesn’t mean that dairy, spices, or sugar actually cause crazy dreams—just that the participants thought that was the case. They did raise an interesting hypothesis, though: These foods could’ve influenced the participants’ dreams by causing gut issues.
A study published in the American Journal of Gastroenterology found that foods that cause GI discomfort limit sleep quality, and this can lead to strange dreams, Gary Wenk, neuroscientist and professor at Ohio State University, tells The Cut.
Wenk does note that some compounds in spices, like nutmeg, have psychoactive properties when you consume them in large amounts—but it’s highly unlikely you’d ever eat enough nutmeg to actually experience this kind of effect. There’s still a possibility that dining on a spicy dish could trigger some type of response in your brain that would result in crazy dreams, though, explains Wenk.
Another reason why your takeout chicken tikka masala could be to blame for your crazy dreams: Robert S. Rosenberg, sleep specialist, tells Women’s Health that spicy foods increase your metabolism and body temperature—and this can boost your brain activity during REM sleep, which is when most of your dreaming takes place.
Now, even if there’s no proof that spicy foods affect your dreams, it’s a good idea to avoid them too close to bedtime because they can cause acid reflux, which can lead to a poor night’s sleep.
5. You just quit taking a medication
Serotonin-norepinephrine reuptake inhibitors (SSRIs), a common class of antidepressants that includes Paxil and Zoloft, suppress the amount of time you spend in REM sleep, according to a study published in Sleep Medicine Reviews. That means you’ll experience fewer dreams if you’re on them. The researchers reported that withdrawal from this type of antidepressant intensifies dreaming.
Another study published in the journal Australian Prescriber also states that quitting SSRIs or serotonin noradrenaline reuptake inhibitors (SNRIs) like Cymbalta, or switching antidepressants, can lead to a variety of side effects including vivid dreams, flu-like symptoms, and irritability.
The researchers stress that switching from one antidepressant to another or quitting a drug altogether should only be done with caution and under the careful observation of your doctor.
6. You binge-watched something scary before bed
If your regular nighttime routine consists of watching episodes of American Horror Story in bed, then that could explain why you’re having crazy dreams. A study published in the journal Dreaming found that consuming violent or sexual content (whether from a TV show, movie, or video game) before bed could result in violent or sexual dreams.
The researchers note that their results are consistent with “cognitive neoassociation theory.” Study co-author Brad Bushman tells Men’s Health that this is the idea that what you watch on a screen triggers related thoughts and memories in your brain.
The National Sleep Foundation advises limiting your TV and computer use before bed and establishing a nighttime routine that doesn’t involve the use of any screens—or maybe try to watch a comedy before bed instead.
What causes vivid dreams to feel so real?
Vivid dreams that feel very real can be triggered by various things, including melatonin supplements, stress and anxiety, sleep disorders, spicy food, and even scary movies. Melatonin supplements and sleep disorders can mess with REM sleep, which is when the brain experiences a spike in activity, causing more bizarre and crazy dreams. On the other hand, stress and anxiety as well as scary movies can trigger certain thoughts, emotions, and memories that can influence your dreams and cause nightmares.
Is it normal to have vivid dreams every night?
Having vivid dreams every night is only harmful if they’re frequently nightmares. If they occur for weeks or months, then they can be mentally and emotionally disruptive and can disturb your sleep. These nightmares could also be an indicator of stress, anxiety, depression, or a sleep disorder.