Sleep paralysis (SP), along with lucid dreaming and out-of-body experiences, is one of the phase states, one that can sometimes be an unpleasant experience. It occurs when falling asleep or waking up: the brain is awake but the body is paralyzed. This is often accompanied by hallucinations, palpitations, heaviness in the chest, anxiety and even fear of dying. The term “isolated sleep paralysis” is used when SP is not a symptom of some other condition (narcolepsy, substance use, etc.).
Researchers from Poland and the UK (Wróbel-Knybel, Rog, Jalal, Szewczyk, and Karakuła-Juchnowicz) were interested in the question of whether sleep paralysis might be related to stress. The authors decided to study firefighters, since this profession entails strong physical and psychological stress. Among firefighters, 37–70% suffer from various sleep disorders (for people in other professions, this figure is usually half as high).
The researchers interviewed 831 people using an online questionnaire. The results showed that 72 participants had experienced at least one episode of sleep paralysis in their lifetime. Therefore, the percentage of firefighters suffering from SP is higher than among the general population (8.7% vs. 7.6%).
Post-traumatic stress disorder is a common cause of sleep paralysis: up to 70% of PTSD sufferers struggle with sleep disorders. This might explain why, the prevalence of SP among students is 28.3%, among psychiatric patients – 31.9%, and among African Americans – 40.2%. As the authors add, it is very important to identify risk groups in order to provide timely assistance.
The article was published in September 2021 in the International Journal of Environmental Research and Public Health.