Psychopathology and NREM sleep parasomnias: A systematic review

Non-rapid eye movement (NREM) sleep parasomnias are abnormal motor and/or emotional behaviors originating from "deep" slow-wave sleep and with a multifactorial origin. The relationship between NREM parasomnias and psychopathology has been a topic of ongoing debate, but a comprehensive and systematic perspective has been lacking. This systematic review, conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA-P) guidelines, aims to fill this gap in the literature. Databases including PubMed, Scopus, Embase, and Web of Science were searched from their inception until March 2024. Only studies written in English were included. We selected case-control studies that reported either psychopathological or neurodevelopmental data in NREM sleep parasomnias, or NREM sleep parasomnia data across different mental disorders, across children and adults. Our review found that psychopathological and neurodevelopmental issues are common in NREM parasomnias, with a higher prevalence in affected patients compared to non-affected individuals. Additionally, NREM parasomnias are more common among patients with various psychopathological conditions than in the general population. Medications did not significantly bias these results. These findings suggest that psychopathological aspects should become a core focus of research and treatment strategies for NREM parasomnias.