REM sleep behaviour disorder (RBD): Personal perspectives and research priorities

Summary The formal identification and naming of rapid eye movement (REM) sleep behaviour disorder (RBD) in 1985–1987 is described; the historical background of RBD from 1966 to 1985 is briefly discussed; and RBD milestones are presented. Current knowledge on RBD is identified with reference to recent comprehensive reviews, allowing for a focus on research priorities for RBD: factors and predictors of neurodegenerative phenoconversion from isolated RBD and patient enrolment in neuroprotective trials; isolated RBD clinical research cohorts; epidemiology of RBD; traumatic brain injury, post‐traumatic stress disorder, RBD and neurodegeneration; depression, RBD and synucleinopathy; evolution of prodromal RBD to neurodegeneration; gut microbiome dysbiosis and colonic synuclein histopathology in isolated RBD; other alpha‐synuclein research in isolated RBD; narcolepsy‐RBD; dreams and nightmares in RBD; phasic REM sleep in isolated RBD; RBD, periodic limb movements, periodic limb movement disorder pseudo‐RBD; other neurophysiology research in RBD; cardiac scintigraphy ( 123 I‐MIBG) in isolated RBD; brain magnetic resonance imaging biomarkers in isolated RBD; microRNAs as biomarkers in isolated RBD; actigraphic, other automated digital monitoring and machine learning research in RBD; prognostic counselling and ethical considerations in isolated RBD; and REM sleep basic science research. RBD research is flourishing, and is strategically situated at an ever‐expanding crossroads of clinical (sleep) medicine, neurology, psychiatry and neuroscience.