Comparative prevalence of isolated sleep paralysis in Kuwaiti, Sudanese, and American college students

A questionnaire measuring the incidence of isolated sleep paralysis was administered to 527 Kuwaiti, 762 Sudanese, and 649 American college students in what was the first study assessing the prevalence of isolated sleep paralysis in two Middle Eastern countries. Using the item "unable to move," 28.8% of Kuwaiti, 29.9% of Sudanese, and 24.5% of American participants reported experiencing the disorder at least once. When a second item, "pressure to the chest," was also used, the respective percentages were 19.2%, 20.7%, and 11.4%. With both criteria, the Kuwaiti and Sudanese had a significantly greater prevalence than did the American students. The Kuwaiti and Sudanese students did not differ significantly from each other in the percentage who reported the symptoms.