Dr. Jimenez-Genchi noted that the sensation was reported as lasting from a few seconds to a minute or so.
The students reported the following frequency of episodes:
- Once in their lifetime in 34.9% of the cases
- 2-3 times in 33.3% of the cases
- More than three times in 6.3% of the cases
- Once a year in 3.2% of cases
- Several times a year in 12.7% of cases
- Once a month in 6.3% of cases
- Several times a week in 3.2% of cases
All the teenagers who participated in the survey also completed a Sleep Paralysis Questionnaire and the Epworth Sleepiness Scale. There was no difference in scores between those who had had a recent event and others who had not had an event recently, Dr. Jimenez-Genchi said.
"These parasomnias are fascinating things to study," said Colleen Walsh, B.S., a post-graduate researcher at the University of Pittsburgh, who also reported on parasomnia events -- nightmares, sleep terrors, sleep walking and sleep talking, and enuresis. "I have friends who describe similar sleep paralysis events."