Relationships between sleep paralysis and sleep quality: current insights.

Sleep paralysis is the experience of waking up unable to move, often accompanied by extreme fear and, in some cases, significant distress. This review of existing literature found that worse subjective sleep quality is consistently associated with higher odds of sleep paralysis. Insomnia symptoms, but not a diagnosed insomnia disorder, also predict its occurrence. Sleep paralysis is linked to other unusual sleep experiences like nightmares, exploding head syndrome, and lucid dreaming. Objective laboratory recordings show sleep paralysis is a mixed state of consciousness, combining elements of rapid eye movement sleep with wakefulness. Future research should use longitudinal designs and broader assessments to better understand the condition.

Study at a glance

Abstract

Sleep paralysis is the unusual experience of waking up in the night without the ability to move. Currently little is known about the experience, despite the fact that the vast majority of episodes are associated with extreme fear and in a minority of cases can lead to clinically significant levels of distress. The aim of this work was to review the existing literature pertaining to the relationship sleep paralysis has to sleep more generally, measured both with subjective questionnaires and objective laboratory recordings. In terms of subjective sleep variables, worse sleep quality has been found in multiple studies to be associated with increased odds of sleep paralysis occurrence. In addition, insomnia symptoms (but not a diagnosed insomnia disorder) have also been found to predict sleep paralysis. Associations between sleep paralysis and other unusual and/or threatening sleep experiences such as nightmares, exploding head syndrome, and lucid dreaming have been reported. In terms of objective measurements, the limited literature to date shows sleep paralysis to be a "mixed" state of consciousness, combining elements of rapid eye movement sleep with elements of wakefulness. Future research needs to focus on longitudinal designs to disentangle the direction of effects and more typically employ a broader assessment of sleep paralysis that better captures associated features such as hallucinations, fear, and distress.