Prevalence and pathologic associations of sleep paralysis in the general population

Background: Previous epidemiologic data on sleep paralysis (SP) came from s mall specific samples. The true prevalence and associated factors of SP in the general population remain unknown. Method: A representative sample of t he noninstitutionalized general population of Germany and Italy age greater than or equal to 15 years (n = 8,085) was surveyed by telephone using the Sleep-EVAL questionnaire and the Sleep Questionnaire of Alertness and Wakef ulness. Results: Overall, 6.2% (5.1 to 6.7%) of the sample (n = 494) had ex perienced at least one SP episode in their lifetime. At the time of the int erview, severe SP (at least one episode per week) occurred in 0.8% of the s ample, moderate SP (at least one episode per month) in 1.4%, and mild SP (l ess than one episode per month) in 4.0%. Significant predictive variables o f SP were anxiolytic medication, automatic behavior, bipolar disorders, phy sical disease, hypnopompic hallucinations, nonrestorative sleep, and noctur nal leg cramps. Conclusions: SP is less common in the general population th an was previously reported. This study indicates that the disorder is often associated with a mental disorder. Users of anxiolytic medication were nea rly five times as likely to report SP, wen after we controlled for possible effects of mental and sleep disorders.