Nightmares

The word "nightmare" dates back to around 1300, initially meaning "an evil female spirit thought to lie on and suffocate men in their sleep; a goblin that causes nightmares; an incubus". In the mid-16th century, the meaning shifted from the incubus to the suffocating sensation it provokes in sleepers. By 1829, the meaning had extended to include any bad dream, and then by 1831, more generally to any very distressing experience.

For the purposes of this Tag, a "nightmare" is a dream with highly distressing content, particularly one where its victim experiences the unpleasant suffocating sensation historically attributed to that "demonic incubus" pressing on the sleeper's chest. Notably, the meaning attributed to the phenomenon of nightmares varies according to one's culture and personal beliefs. Scientifically speaking, nightmares are caused by both physiological and psychological factors and manifest almost exclusively during REM sleep. In some circumstances, they can constitute a true psychopathology (the so-called "nightmare disorder", not to be confused with "sleep terror disorder"), which primarily afflicts children exposed to prolonged psychosocial stressors.

This Tag unites a number of films characterized by a significant presence of disturbing dreams and parasomnias, with a particular interest in terrifying dreams or dreams that portend foreboding events. On the silver screen, particularly in thrillers and horror films, sleep ceases to be synonymous with rest, and rather than performing a restorative function, it becomes the stage for apprehension and horror. For films in a more realistic vein, the emphasis shifts to the sleeper's vulnerability (a defenseless individual unaware of looming peril). The opposite holds true for tales with a marked fantasy/supernatural component, which instead play up the nightmare theme, often turning the disturbing dream into a harbinger of real-life events (an extreme case being the "Nightmare" saga's Freddy Krueger, a bogeyman whose actions in the oneiric realm can have deadly repercussions on the sleeper).