Also known as RBD, REM sleep behavior disorder is where normal sleep paralysis doesn’t happen during REM sleep, so to varying degrees, a person might ‘act out’ what they’re dreaming.
Three additional dogs were found with presumed RBD in the classic films Lady and the Tramp (1955) and The Fox and the Hound (1981), and in the short Pluto’s Judgment Day (1935). These dogs were elderly males who would pant, whine, snuffle, howl, laugh, paddle, kick, and propel themselves while dreaming that they were chasing someone or running away. In Lady and the Tramp the dog was also losing both his sense of smell and his memory, two associated features of human RBD. These four films were released before RBD was first formally described in humans and dogs.
In addition, systematic viewing of the Disney films identified a broad range of sleep disorders, including nightmares, sleepwalking, sleep related seizures, disruptive snoring, excessive daytime sleepiness, insomnia and circadian rhythm sleep disorder. These sleep disorders were inserted as comic elements. The inclusion of a broad range of accurately depicted sleep disorders in these films indicates that the Disney screenwriters were astute observers of sleep and its disorders.
This is not the first time that Disney films have featured in the medical literature.
One 2004 study published in the Canadian Journal of Psychiatry looked at the representation of mental illness in Disney movies (and found, rather disappointingly, that mental illness was typically referred to when one character was denigrating another).