The REM Sleep Behavior Disorder Single-Question Screen offers diagnostic sensitivity and specificity in the absence of polysomnography with one question: "Have you ever been told, or suspected yourself, that you seem to act out your dreams while asleep (for example, punching, flailing your arms in the air, making running movements, etc.)?" Diagnostic criteria for RBD from the International Classification of Sleep Disorders (ICSD-3) are:
Repetition of vocalizations and/or complex motor behaviors during sleep
Polysomnography (PSG) show that these behaviors occur during REM sleep
If documentation of these behaviors by PSG is not possible, they must at least be assumed to take place during REM sleep based on records of dream enactment
REM sleep without atonia (RWA) can be seen in polysomnographic recordings
Episodes cannot be explained by another mental disorder, sleep disorder, substance abuse or medication

Differential
Other conditions are similar to RBD in that individuals exhibit excessive sleep movement and potentially violent behavior. Such disorders include non-REM parasomnias (sleepwalking, sleep terrors), periodic limb movement disorder, severe obstructive sleep apnea, and dissociative disorders. Because of the similarities between the conditions, polysomnography plays an important role in confirming RBD diagnosis. Treatment
RBD is treatable (even when the underlying synucleinopathies are not). Melatonin and clonazepam are the most frequently used, and are comparably effective, but melatonin offers a safer alternative, because clonazepam can produce undesirable side effects.
It is more common in males overall, but equally frequent among men and women below the age of 50. This may partially be due to a referral bias, as violent activity carried out by men is more likely to result in harm and injury and is more likely to be reported than injury to male bed partners by women, or it may reflect a true difference in prevalence as a result of genetic or androgenic factors. Typical onset is in the 50s or 60s.Almost half of those with Parkinsons, at least 88% of those with multiple system atrophy, and about 80% of people with Lewy body dementia have RBD. RBD is a very strong predictor of progression to a synucleinopathy (for example, the Lewy body dementias). On autopsy, up to 98% of individuals with polysomnography-confirmed RBD are found to have a synucleinopathy. History
In the 1960s and 1970s, Michel Jouvet described brain lesions in cats that led to loss of atonia in REM sleep. Carlos Schenck and Mark Mahowald and their team in Minnesota first described RBD in 1986. In animals
RBD has also been diagnosed in animals; specifically dogs. See also
Sleepwalk with Me
Pseudobulbar affect
Gelastic seizure

References
Further reading
Roguski A, Rayment D, Whone AL, Jones MW, Rolinski M (2020). "A Neurologists Guide to REM Sleep Behavior Disorder". Front Neurol (Review). 11: 610. doi:10.3389/fneur.2020.00610. PMC 7360679. PMID 32733361.