Psychologists chase down sleep demons

What do Moby Dick, the Salem witch trials and alien abductions all have in common? They all circle back to sleep paralysis.

Less than 8 percent of the general population experiences sleep paralysis, but it is more frequent in two groups — students and psychiatric patients — according to a new study by psychologists at Penn State and the University of Pennsylvania.

Sleep paralysis is defined as “a discrete period of time during which voluntary muscle movement is inhibited, yet ocular and respiratory movements are intact,” the researchers state in the current issue of Sleep Medicine Reviews. Hallucinations may also be present in these transitions to or from sleep.

Alien abductions and incubi and succubi, as well as other demons that attack while people are asleep, are implicated as different cultural interpretations of sleep paralysis. The Salem witch trials are now thought possibly to involve the townspeople experiencing sleep paralysis. And in the 19th-century novel Moby Dick, the main character Ishmael experiences an episode of sleep paralysis in the form of a malevolent presence in the room.

Brian A. Sharpless, clinical assistant professor of psychology and assistant director of the psychological clinic at Penn State, noted that some people who experience these episodes may regularly try to avoid going to sleep because of the unpleasant sensations they experience. But other people enjoy the sensations they feel during sleep paralysis.

“I realized that there were no real sleep paralysis prevalence rates available that were based on large and diverse samples,” Sharpless said. “So I combined data from my previous study with 34 other studies in order to determine how common it was in different groups.”

He looked at a total of 35 published studies from the past 50 years to find lifetime sleep paralysis rates. These studies surveyed a total of 36,533 people. Overall he found that about one-fifth of these people experienced an episode at least once. Frequency of sleep paralysis ranged from once in a lifetime to every night.

When looking at specific groups, 28 percent of students reported experiencing sleep paralysis, while nearly 32 percent of psychiatric patients reported experiencing at least one episode. People with panic disorder were even more likely to experience sleep paralysis, and almost 35 percent of those surveyed reported experiencing these episodes. Sleep paralysis also appears to be more common in non-Caucasians.

“Sleep paralysis should be assessed more regularly and uniformly in order to determine its impact on individual functioning and better articulate its relation to other psychiatric and medical conditions,” said Sharpless.

He looked at a broad range of samples, and papers were included from many different countries.

People experience three basic types of hallucinations during sleep paralysis — the presence of an intruder, pressure on the chest sometimes accompanied by physical and/or sexual assault experiences and levitation or out-of-body experiences.

Up to this point there has been little research conducted on how to alleviate sleep paralysis or whether or not people experience episodes throughout their lives.

“I want to better understand how sleep paralysis affects people, as opposed to simply knowing that they experience it,” said Sharpless. “I want to see how it impacts their lives.” Sharpless hopes to look at relationships between sleep paralysis and post-traumatic stress disorder in the future.

This research was supported in part by the National Institute of Mental Health.

Also working on this research was Jacques P. Barber, professor of psychiatry, University of Pennsylvania.

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37 thoughts on “Psychologists chase down sleep demons”

  1. I have narcolepsy, meaning that i go into REM sleep within 4 minutes of falling asleep other symptoms include cataplexy(loss of muscle control upon an emotional trigger), hallucinations while sleeping and sleep paralysis. When i don’t take my medication the symptoms were seen almost everyday/night. I have experienced the heaviness on my chest, seeing something in the room most of the time it feels as if its something evil but there have been a few where it is just funny. Ex: barbie and bert making out. It started making me not want to go to sleep in the dark. I had a tramatic experience when I was about 13, I dont and never have liked not being in control of a situation which may be partially to explain why i am so scared when it happens. Have you found that people can have it happen and not get scared? Do you believe that some are able to “think” their way out of it?

  2. Several years ago whenever I would start to fall asleep, I would get an odd sensation that I was about to leave my body. I would try to fight to keep that from happening and even though I thought I was awake and it was over it really wasn’t. It would take me awhile to actually wake up and then I would be too afraid to try to fall back to sleep because it would happen again. Although every night I would tell myself that I was just going to try to relax and let it happen so I could find out where it would lead, like I might travel around, but when it started I would panic and not let it happen. I guess I thought I was going to die It doesn’t happen to me anymore and I am so mad at myself because I never let myself experience what might have happened. I sometime still wish that I could make it happen but it doesn’t work. I have asked other people if they ever experienced anything like that but nobody I asked ever had. I thought I was the only one who ever went through anything like that until I read this article.

  3. I have experienced SP plenty of times. It usually gets more frequent when I am under a lot of stress or the room is really dark. I have tried to give in and just fall asleep through it but it is very scary because I am not sure what is causing these episodes. My mind is awake and its starts to scramble to find an explaination as to why this is happening, and what will happen if I let it be. My dad gets them often as well and he told me his method of “waking up” from it. His instructions: start to wake up your body by breathing very hard. Then try to move your toes/feet and slowly try to get control of the rest of your body. His method does work to wake up my body but if I try to go back to sleep right away I fall back into SP. I usually try to distract my mind by reciting prayer, surfing the internet, or watching tv.

  4. I have experience this, myself, older sister and my two little brothers, the presence of someone holding u dwn and u cant break free and it always feels evil, one of my little brothers hav out of body experiences and one of them actually saw wat was holding him dwn and screamed so hard he jumped out of his sleep and ran str8 in my bed….I kno some ppl believe tht there is a scientific explanation for everything but for me and most ppl i kno that have experienced this, the last ting on ur mind during one of these episodes is science…..i rmbr being wide awake (eyes closed) n feeling a creeping sensation run st8 up my body and being frozen instantly and hearing whispers in my ears but i cant understand wats being said….one my little brother is so terrified of this thing tht he watches TV as long as he can to prevent falling asleep. like a few ppl here i hav discovered tht if i jus let it happen its less intense but it takes alot to just let urself go while this is happening….my brother told me tht he tried tht once but instead of it getting better he felt like something was pulling him out of his body and he had to fight to stay in!….

    • Devout Christian and yet been having this dream for the last 5 years. Somebody grabbing my feet trying to pull me out of my body. I have to fight extremely hard not to get out!!!!

  5. speaking from experience, once i became a christian and repented and trusted Jesus Christ as my lord and saviour it has 100% stopped…there is no question it is a demonic presence.

    • Really? Because I was a devout Christian when it began. I don’t believe that applies to everyone who experiences this.

  6. Do you really think it’s a glitch in our brains, when we’re going from sleep to waking? Or do you think it’s a spiritual thing?

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