Sleep scientists believe that sleep paralysis may occur when the transitions in and out of REM sleep and other sleep stages don’t go smoothly. The paralysis that is typically confined to REM sleep spills over to other sleep stages — and if you wake, you become aware of your body’s paralysis, and the frightening feeling of being unable to move or to speak. Sleep paralysis may also include hallucinations. People often describe feeling a ghost-like presence in the room with them, as well as feelings of terror and foreboding. These hallucinations can include strange sounds and even smells, along with sensations of falling or flying. Although the mechanisms of breathing aren’t impaired by sleep paralysis, people sometimes feel breathless, and often feel a weighty pressure on the chest. The experience of sleep paralysis can be terrifying, especially the first time it occurs.
New research investigates possible factors that contribute to sleep paralysis — and the results indicate that genetics may play a significant role. Scientists in the United Kingdom examined the role of heredity in sleep paralysis among a group of 862 twins and siblings. The participants were young adults between the ages 22 and 32, all of whom were enrolled in the Genesis 12-19 study, a long-term, ongoing U.K.-based investigation of genetics and development.
To pinpoint the role that heredity might play, researchers compared data on sleep and the incidence of sleep paralysis for identical twins to data involving non-identical twins and siblings. Identical twins carry almost exactly the same DNA, while non-identical twins and siblings have roughly 50 percent of DNA in common. Their analysis found that genetics was a factor in 53 percent of cases of sleep paralysis among their subjects.
Researchers examined this genetic link more closely by looking at variants of a gene that is involved in control of circadian rhythms, the 24-hour biological rhythms that help to govern sleep-wake cycles. They discovered that people with certain variations of the PER2 gene were more likely to have experienced sleep paralysis. The study also found people with disrupted sleep, as well as people who experienced anxiety, stressful or traumatic events were more likely to suffer episodes of sleep paralysis.
These findings align with previous research suggesting family links to sleep paralysis, as well as to research indicating stress, trauma, anxiety and depression make sleep paralysis more likely. This latest study gives new direction to explore more closely the connection between sleep paralysis and the genes that drive circadian rhythms.
You can help decrease your chances of experiencing sleep paralysis by focusing on the fundamentals of healthy sleep: maintaining a regular sleep routine, avoiding stimulants (especially alcohol), exercising regularly, eating well and avoiding eating late at night. It’s also important to tend carefully to stress and to your mental health. Anxiety and depression are common. Seeking treatment for these conditions can help you sleep better overall, and may help you avoid sleep paralysis.
If you do experience sleep paralysis, don’t panic. Remind yourself that however frightening and disconcerting, this is a temporary and harmless condition that will soon pass. Understanding what’s happening to you physiologically can help you avoid the worst of the fear associated with this scary sleep phenomenon.
Michael J. Breus, PhD
The Sleep Doctor™