REM Sleep Disorders and Their Relationship with Mental Disorders: A Critical Narrative Review

Rapid eye movement (REM) sleep is a physiologically distinct sleep stage implicated in emotional memory processing, mood regulation, and cognitive consolidation. Since its discovery seven decades ago, disruptions in REM sleep architecture and REM-associated parasomnias have repeatedly been linked to a broad spectrum of psychiatric conditions. This critical narrative review synthesizes evidence on the relationship between REM sleep disturbances — including altered REM latency, density, and volume, REM sleep behavior disorder (RBD), and nightmare disorder — and major depressive disorder, bipolar disorder, anxiety-related disorders and post-traumatic stress disorder (PTSD), and schizophrenia. The evidence converges on REM sleep dysregulation as a transdiagnostic feature across affective and psychotic disorders, with shortened REM latency and increased REM density most consistently reported in depression, while RBD emerges both as a marker of neurodegenerative risk and as a correlate of broader psychiatric distress. Mechanistically, REM sleep's role in overnight emotional-memory consolidation and fear extinction offers a plausible bridge between disrupted REM physiology and mood and anxiety symptoms, and underlies emerging REM-targeted interventions such as imagery rehearsal therapy and targeted memory reactivation. The literature, however, remains constrained by heterogeneous diagnostic criteria, small and largely cross-sectional samples, medication confounds, and inconsistent operationalization of “REM abnormality.” The review closes by outlining directions for more rigorous, longitudinal, and mechanism-focused research at the interface of sleep medicine and psychiatry.

کلیدواژه ها:

REM sleep ، REM sleep behavior disorder ، depression ، anxiety ، PTSD ، schizophrenia ، nightmares ، emotion regulation