Prevalence and pathologic associations of sleep paralysis in the general population.

About 6.2% of the general population in Germany and Italy has experienced at least one episode of sleep paralysis, with 0.8% experiencing severe episodes (at least one per week). Sleep paralysis is less common than earlier small-sample studies suggested. The condition is often linked to mental disorders; users of anxiolytic medication were nearly five times as likely to report sleep paralysis, even after accounting for mental and sleep disorders. Other predictive factors include automatic behavior, bipolar disorders, physical disease, hypnopompic hallucinations, nonrestorative sleep, and nocturnal leg cramps.

Study at a glance

Abstract

Previous epidemiologic data on sleep paralysis (SP) came from small specific samples. The true prevalence and associated factors of SP in the general population remain unknown. A representative sample of the noninstitutionalized general population of Germany and Italy age > or =15 years (n = 8,085) was surveyed by telephone using the Sleep-EVAL questionnaire and the Sleep Questionnaire of Alertness and Wakefulness. Overall, 6.2% (5.7 to 6.7%) of the sample (n = 494) had experienced at least one SP episode in their lifetime. At the time of the interview, severe SP (at least one episode per week) occurred in 0.8% of the sample, moderate SP (at least one episode per month) in 1.4%, and mild SP (less than one episode per month) in 4.0%. Significant predictive variables of SP were anxiolytic medication, automatic behavior, bipolar disorders, physical disease, hypnopompic hallucinations, nonrestorative sleep, and nocturnal leg cramps. SP is less common in the general population than was previously reported. This study indicates that the disorder is often associated with a mental disorder. Users of anxiolytic medication were nearly five times as likely to report SP, even after we controlled for possible effects of mental and sleep disorders.