Manifestation of Sleep Paralysis among Clinical and Non-Clinical Population; A Comparative Study

Sleep paralysis is a transient condition of inability to move or speak during sleep-wake transitions. A comparative cross-sectional study of 90 participants from Rawalpindi and Islamabad, equally divided among clinical (neurotic and psychotic disorders) and non-clinical groups, found no significant differences across groups in intruder and incubus experiences. However, vestibular-motor experiences (sensations of movement or floating) were significantly more intense and frequent in the psychotic group. Intruder and incubus experiences were common across all groups, suggesting these phenomena are widespread regardless of psychiatric diagnosis.

Study at a glance

Abstract

Background: Sleep paralysis is a transient and often distressing condition characterized by an inability to move or speak during the transition between wakefulness and sleep. Previous studies have highlighted a higher prevalence of sleep paralysis in psychiatric populations compared to the general population, yet comprehensive comparative studies remain scarce. Understanding the nuances of sleep paralysis across different populations is crucial for developing targeted interventions. Objective: This study aims to compare the manifestation of sleep paralysis among clinical (neurotic and psychotic disorders) and non-clinical populations, with a specific focus on the prevalence of intruder, incubus, and vestibular-motor experiences. Methods: A comparative cross-sectional design was employed, with a sample size of 90 participants, equally divided among clinical (neurotic and psychotic) and non-clinical groups from Rawalpindi and Islamabad. The study utilized purposive sampling for participant selection. Individuals aged 14 years and above, diagnosed with neurotic disorders, brief psychotic disorder, early psychosis, or those experiencing sleep paralysis without a mental disorder diagnosis were included. The Waterloo Unusual Sleep Experiences Questionnaire-IX (WQ) along with diagnostic scales for depression, anxiety, panic attacks, and psychotic disorders were administered. Data analysis was conducted using IBM SPSS Statistics version 25, employing descriptive statistics, ANOVA, and Chi-Square tests. Results: The mean age of participants was 22.21 (SD = 4.318). Gender distribution was 54.4% male and 45.6% female. The ANOVA results indicated no significant differences in the intruder and incubus experiences across groups. However, a significant difference was found in the intensity and frequency of vestibular-motor experiences, with F values of 6.684 (p<.01) and 9.231 (p<.01), respectively. Chi-square analysis further highlighted significant differences in the manifestation of sleep paralysis, with vestibular-motor experiences being notably higher among the psychotic group. Conclusion: The study confirms the higher prevalence of vestibular-motor experiences of sleep paralysis among clinical populations, particularly those with psychotic disorders, compared to non-clinical populations. Intruder and incubus experiences were commonly reported across all groups, indicating a widespread presence of these phenomena regardless of psychiatric diagnosis.