Lifetime prevalence and characteristics of sleep paralysis in Italian university students population

Sleep paralysis (SP) is a REM-related parasomnia, characterized by the inability to perform voluntary movements. It is a relatively widespread phenomenon in the general population and, although usually not dangerous, it is experienced with intense fear. The current study aims to evaluate the lifetime prevalence and characteristics of SP in the Italian student population. The study was conducted online, through an online battery of questionnaires. We used the Unusual Sleep Experience Questionnaire to investigate the prevalence of the disorder and the typical characteristics, metacognitive beliefs on the episodes, and previous distress factors. We also collected information about anxiety and depression symptomatology, sleep quality, and circadian preferences. Four hundred and thirty-two participants (333 F, 22.8 +/- 2.57 y) took part in the study and 37.5 % of them reported having experienced at least one SP episode in their lifetime. On a physiological level, the most common features were the inability to speak followed by a tingling sensation and the inability to open the eyes, consistent with REM muscle atonia. Cognitive features during episodes include the perception of a presence in the room, followed by the fear of dying. Participants who reported SP had higher anxiety and worse sleep quality, and were more associated with evening chronotypes compared to non-SP responders. Our results show that SP is generally widespread in Italian students, in line with the prevalence reported in previous studies. Further studies could investigate the effects of suggested therapies to decrease the number of episodes of the disorder, especially in those who experience it recurrently.