Prevalence and Clinical Picture of Sleep Paralysis in a Polish Student Sample

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.

Experiences and beliefs related to sleep paralysis among the general population of the twin cities: A cross-sectional study

BACKGROUND

Sleep paralysis (SP) is a rapid eye movement (REM) parasomnia that occurs during the transition between wakefulness and sleep. During this brief state, a person is conscious but unable to move or speak, often experiencing hallucinations. It is 'isolated' when it occurs without other symptoms of narcolepsy or sleep disorders. Despite its prevalence, much remains unknown about its clinical features and associated beliefs.

OBJECTIVES

This study examines the frequency of self-reported SP experiences and its associated demographic characteristics, along with participants' beliefs about the condition.

METHODS

A cross-sectional survey was conducted among visitors at a shopping mall, using the Unusual Sleep Experiences Questionnaire (USEQ) to assess the features of SP episodes and the common beliefs surrounding them.

RESULTS

A total of 350 participants were surveyed (mean age = 25.5 ± 9.30 years; 55.4 % females). Participants who experienced SP at least once in their life time (39.1 %) reported feeling pressure on their chest (67.2 %), an inability to open their eyes (71.5 %), and difficulty speaking (81.0 %) during the episode. The majority of the individuals reported having their first episode at a young age (16-20 years). Most people (24.5 %) were unaware that this condition was known as sleep paralysis, and many (23.5 %) thought that it was just 'a dream'.

CONCLUSION

Isolated sleep paralysis episodes are fairly prevalent, with many people experiencing their first episode at a young age. A typical episode entails a sense of pressure on the chest and difficulty in vocalizing. Misconceptions about the condition are common and wage further exploration.

Prevalence and Clinical Characteristics of Sleeping Paralysis: A Systematic Review and Meta-Analysis

Sleep paralysis (SP) is a mixed state of consciousness and sleep, combining features of rapid eye movement (REM) sleep with those of wakefulness. The exact cause of SP is unknown, and its prevalence varies among the studies. We aim to identify SP's global prevalence, the affected population's characteristics, and the SP's clinical picture. We searched three databases (PubMed, Scopus, and Web of Science (WoS)) using a unique search strategy to identify eligible studies. All observational studies identifying the prevalence or frequency of sleeping paralysis were included. No exclusions are made based on country, race, or questionnaire. The analysis was performed using the latest version of R software (R Core Team, Vienna, Austria). The analysis included 76 studies from 25 countries with 167,133 participants. The global prevalence of SP was 30% (95% CI (22%, 39%)). There were similar frequencies of isolated SP and SP (33%, 95% CI (26%, 42%), I2 = 97%, P <0.01; 31%, 95% CI (21%, 43%), I2 = 100%, P = 0, respectively). A subgroup analysis showed that the majority of those who experienced SP were psychiatric patients (35%, 95% CI (20%, 55%), I2 = 96%, P <0.01). The prevalence among non-psychiatric patients was among students (34%, 95% CI (23%, 47%), I2 = 100%, P = 0). Auditory and visual hallucinations were reported in 24.25% of patients. Around 4% had only visual hallucinations. Meta-regression showed no association between the frequency of SP and sex. Publication bias was detected among the included studies through visual inspection of funnel plot asymmetry. Our findings revealed that 30% of the population suffered from SP, especially psychiatric patients and students. The majority of SP cases lacked associated hallucinations, while a noteworthy proportion experienced combined visual and auditory hallucinations.

The prevalence of sleep paralysis in medical students in Buenos Aires, Argentina

Objectives

The objectives of this study were to determine the prevalence of sleep paralysis (SP) in medical students from the University of Buenos Aires (UBA).

Materials and Methods

An ad hoc questionnaire based on the diagnosis of SP and a demographic survey was electronically presented to students of Internal Medicine at the School of Medicine of the UBA. The respondents answered both questionnaires using Google Forms®.

Results

The prevalence of SP was 40.7% (95% CI 33.5-47.8). A higher percentage of the respondents (76%) reported experiencing SP-related anxiety. An association between self-perceived quality of sleep and the incidence of SP was found (χ2: 12.712, P = 0.002). The highest frequency was hypnopompic SP (55.55%), and the highest percentage (55.4%) suffered from SP less than once every 6 months. Most respondents (59.5%) reported having started with SP symptoms after 18 years of age, and the highest percentage (66.2%) had exacerbated their symptoms at college. The frequency of the Incubus phenomenon was 14.5% (95% CI 6.2-23). Most respondents (70.8%) denied the association of SP with religious or paranormal beliefs.

Conclusion

SP is highly prevalent in medical students and is associated with poor sleep habits and perceived poor sleep quality. Clinicians should be aware of this parasomnia to avoid a misdiagnosis of psychosis and inform sufferers of the nature of SP.

Characteristics of Sleep Paralysis and Its Association with Anxiety Symptoms, Perceived Stress, PTSD, and Other Variables Related to Lifestyle in Selected High Stress Exposed Professions

Sleep paralysis (SP) is a hypnagogic or hypnopompic state associated with the inability to move while conscious. Recurrent isolated sleep paralysis (RISP) is a type of REM parasomnia. Individuals experiencing anxiety disorders, PTSD, exposure to chronic stress, or shift work are at risk of developing this sleep disorder. This study aimed to assess: (1) the prevalence, frequency, and symptomatology of SP, and (2) the impact of the severity of anxiety symptoms, perceived stress, and lifestyle mode variables on the frequency and severity of SP in four professional groups at high risk of SP (n = 844): nurses and midwives (n = 172), policemen (n = 174), teachers (n = 107), and a group of mixed professions—“other professions” (n = 391). The study used a battery of online questionnaires: the Sociodemographic and Health Status Questionnaire, the SP-EPQ, the PCL -5, the STAI-T, the PSWQ and the PSS-10. The prevalence of SP was the lowest among policemen (15.5%) and the highest in the group of “other professions” (39.4%). The association of SP with symptoms of PTSD and anxiety was confirmed in the group of nurses and “other professions”. Among other factors modulating the incidence and severity of SP were: age, BMI, smoking, alcohol consumption, sleep duration, and perceived stress. This study indicates that there exist links between SP and psychological and lifestyle factors, suggesting a complex etiology for this sleep disorder. Due to the high prevalence of SP in the studied groups of occupations, further research is necessary to develop preventive and therapeutic methods for SP.

Risk factors of sleep paralysis in a population of Polish students

BACKGROUND

Sleep paralysis (SP) is a transitional dissociative state associated with the REM sleep phase that affects approximately 28.3% of the student population during their lifetime. The reasons for the high prevalence of SP in the student population are not entirely clear. Research indicates possible influencing factors such as the intensification of anxiety symptoms, a tendency to worry, the presence of PTSD symptoms, and behavioral factors such as the consumption of psychoactive substances (caffeine, alcohol, nicotine), sleep deprivations and poor sleep hygiene. The study aimed to assess the prevalence of SP and determine the risk factors for the occurrence of SP in the population of Polish students.

METHODS

The study used a battery online consisting of a set of questionnaires 1) a personal questionnaire, 2) the SP-EPQ, 3) the PCL -5, 4) the STAI-T, 5) the PSWQ. The questionnaire was sent via Facebook to 4500 randomly selected students from different universities in Poland. The questionnaire was completed by 2598 students. To unify the participant sample, people over 35 were excluded from the study (45 students). Ultimately, data from 2553 students were analyzed.

RESULTS

A total of 33.14% of individuals experienced at least one episode of SP in their lives. The highest odds ratio for SP was associated with: the presence of three or more health problems (OR: 2.3; p = 0.002), the presence of any mental disorder (OR: 1.77; p = 0.002), including mood disorders (OR: 2.07; p = 0.002), suffering from at least one somatic disease (OR: 1.34; p = 0.002), a high level of anxiety as a constant personality trait (OR: 1.20; p = 0.035) and smoking (OR: 1.48; p = 0.0002), alcohol consumption (OR: 1.52; p < 0.0001), physical activity (OR: 1.31; p = 0.001).

CONCLUSIONS

The results of our research indicate that a large proportion of students experienced isolated sleep paralysis. Mental and somatic health problems and lifestyle factors were found to predispose individuals to this disorder. Due to the numerous risk factors for SP, it is necessary to conduct additional research to confirm the impact of these factors and to investigate the mechanisms of their influence on SP.

A German online survey of people who have experienced sleep paralysis

We present some key findings from an online survey on isolated sleep paralysis. The aim of our study was to get a differentiated picture of the correlation between the frequency of sleep paralysis and several phenomena (symptoms, experiences) as well as factors correlated with these phenomena. We also investigated the role of gender in relation to the experience of sleep paralysis. We used a selected sample of subjects who had had at least one sleep paralysis experience, with a total of 380 subjects. On average, the participants experienced 10-20 sleep paralysis episodes. We found high and expected positive correlations between the frequency of sleep paralysis experiences and the amount of phenomena, emotions, and perceived shapes and forms experienced during sleep paralysis. An increased frequency of sleep paralysis also appears to lead to habituation and de-dramatization in some affected individuals. Interestingly, significant correlations are missing where one would have suspected them based on the previous hypotheses. Neither self-perceived general stress nor poor sleep hygiene appeared to influence the frequency of sleep paralysis. We found highly significant gender differences in some items. Women reported more experienced phenomena and emotions overall, had more frequent sleep paralysis experiences of the intruder and incubus type, and were significantly more likely to perceive concrete forms such as human figures or people they know. They were also more likely than men to report experiencing fearful emotions, especially the fear of going crazy. Most of these findings were based on exploratory questions; they require replication for validation.

Sleep Paralysis among Professional Firefighters and a Possible Association with PTSD-Online Survey-Based Study

The prevalence of sleep paralysis (SP) is estimated at approximately 7.6% of the world’s general population. One of the strongest factors in the onset of SP is PTSD, which is often found among professional firefighters. Our study aimed to assess in the professional firefighter population (n = 831) (1) the prevalence of SP, (2) the relationship between SP and PTSD and (3) the relationship between SP and other factors: the severity of the stress felt, individual tendency to feel anxious and worried and lifestyle variables. The incidence of SP in the study group was 8.7%. The high probability of PTSD was found in 15.04% of subjects and its presence was associated with 1.86 times the odds of developing SP [OR = 1.86 (95% CI: 1.04–3.33); p = 0.04]. Officers who experienced at least 1 SP during their lifetime had significantly higher results in the scales: PCL-5, STAI-T, PSWQ. The number of SP episodes was positively correlated with the severity of symptoms measured by the PCL-5, PSS-10, STAI and PSWQ questionnaires. Further research is needed to assess the importance of SP among the firefighter population in the context of mental and somatic health and to specify methods of preventing SP episodes.