Exploring the Potential Causes of Sleep Paralysis
Have you ever woken during the night and felt paralyzed or unable to breathe? Maybe you’ve seen a person or demon-like figure in the room after waking or had an out-of-body experience. If so, you may have experienced the symptoms of sleep paralysis. If this happens regularly, it's a good idea to try identifying the cause of your sleep paralysis episodes to help prevent them from happening again in the future.
Reviewing sleep paralysis
In 2017, researchers published a systematic review that aimed to identify the potential causes of sleep paralysis. A total of 42 studies were reviewed and the findings were published in the journal Sleep Medicine Reviews.
Age, gender, and ethnicity
The review reported that studies have generally found no significant effect of age or gender on sleep paralysis prevalence. Mixed evidence was found when it came to the influence of ethnicity on the incidence of sleep paralysis - one study found African-Americans were more likely to experience sleep paralysis compared to Caucasians, while a separate study found that non-Caucasians were more likely to experience sleep paralysis compared to Caucasians.
Location, wealth, and morning meals
A Chinese study found sleep paralysis was more common among teenagers who lived in a rural areas compared to urban areas. Having more money also had a small but significant association with the presence of sleep paralysis, while those who regularly ate breakfast (rather than only eating breakfast occasionally) were less likely to experience sleep paralysis. The review suggested that skipping breakfast routinely may disrupt the sleep/wake cycle and increase sleep paralysis risk.
Alcohol and smoking
Two large, nationwide studies in China found that those who drank at least one alcoholic drink per day over the last month were significantly more likely than others to report sleep paralysis. With that being said, a study out of the UK found that alcohol consumption did not predict sleep paralysis. Another study found increased odds of experiencing sleep paralysis for those who smoked at least one cigarette per day. Two other studies found no such relationship.
Stress and trauma
The review found that a history of childhood sexual abuse was found to be significantly related to the frequency of sleep paralysis episodes. A PTSD diagnosis, anxiety disorders such as panic disorder and stressful events such as experience of war, assault, death of a loved one, and disasters were also associated with sleep paralysis events.
Is sleep paralysis hereditary?
The authors of the review found there was a moderate genetic influence when it came to the presence of sleep paralysis. Other studies have also found a familial association for sleep paralysis.
Physical and mental health
Studies have not found a link between a specific health problem and sleep paralysis, however the review found that general physical health problems appeared to be associated with the sleep disorder. Complaints of chronic pain were linked to sleep paralysis, while poorer general mental health was significantly associated with sleep paralysis frequency.
Imagination and intelligence
The review identified one study that found those with more imagination (as measured by factors including fantasy proneness, magical thinking, imagery vividness, paranormal and mystic beliefs, and unusual sensory experiences) experienced more frequent and intense episodes of sleep paralysis. A separate study found that lower levels of intelligence (as measured by IQ) were also associated with sleep paralysis.
Sleep duration and sleep position
Sleep paralysis was found to be more common among those who went to bed after midnight, took longer than half an hour to fall asleep, and slept on their backs. Sleep durations of under six hours and over nine hours and naps of more than two hours were also associated with increased odds of sleep paralysis.
Sleep paralysis solutions
The authors of the review suggested that since stress and anxiety appear to be linked with sleep paralysis, techniques that reduce these factors (such as cognitive behavioral therapy) may be helpful. Since poor sleep quality was shown to be consistently related to sleep paralysis, sleep hygiene education may also be beneficial.