Nightmares may be the source of all horror. There’s a theory that sleep paralysis may be to blame for history’s waking nightmares: ghosts, demons, specters. We dive into this horrifying complex and the horror films it has inspired.

5. The Night House (2020)

Director David Bruckner’s The Night House rests on a trusted horror foundation that’s adorned with several stylishly creepy fixtures. A remarkable as always Rebecca Hall plays the recently, startlingly widowed Beth whose grief combines with nightmares, sleuthing with doubt.

Though Beth’s neighbor (Vondie Curtis-Hall, always a pleasure) and best friend (Sarah Goldberg) both warn her not to fill the void in her life with “something dark,” the dark keeps calling. The more Beth digs into things Owen left behind, the more signs point to an unsettling secret life, and to the possibility that Owen may not have entirely moved on.

Beth’s sustained grief, and her indignation toward everyone who’s not Owen, carries an authenticity that gets us squarely behind Beth’s personal journey. And that pays dividends once the film relies on our belief in what Beth believes. Thanks to Hall, we end up buying in.

4. Insidious (2010)

Director James Wan and writer (and co-star) Leigh Whannell launched a second franchise with this clever, creepy, star-studded flick about a haunted family.

Patrick Wilson (who would become a Wan/Whannell staple) and Rose Byrne anchor the film as a married couple dealing with the peculiar coma-like state affecting their son, not to mention the weird noises affecting their house. The catch in this sleep paralysis film is that we are not with the dreamer. Instead, the dreamer is an innocent, helpless child, combining the hallucinatory imagery with child-in-peril tension.

But what makes this particular film so effective is that we get to go into The Further to reclaim the lost soul. It’s a risky move, but these filmmakers do what few are able to: they show us what we are afraid of.

3. A Nightmare on Elm Street (1984)

Teens on suburban Elm St. share nightmares, and one by one, these teens are not waking up. Not that their disbelieving parents care. When Tina woke one night, her nightgown shredded by Freddie’s razor fingers, her super-classy mother admonished, “Tina, hon, you gotta cut your fingernails or you gotta stop that kind of dreamin’. One or the other.”

Depositing a boogieman in your dreams to create nightmares that will truly kill you was a genius concept by writer/director Craven because you can only stay awake for so long. It took everyone’s fear of nightmares to a more concrete level.

The film was sequeled to death, it suffers slightly from a low budget and even more from a synth-heavy score and weak FX that date it, but it’s still an effective shocker. That face that stretches through the wall is cool, the stretched out arms behind Tina are still scary. The nightmare images are apt, and the hopscotch chant and the vision of Freddie himself were not only refreshingly original but wildly creepy.

2. Borgman (2013)

Writer/director Alex van Warmerdam delivers a surreal, nightmarish, sometimes darkly comical fable guaranteed to keep you off balance. It is meticulously crafted and deliberately paced, a minefield of psychological torment.

van Warmerdam offsets his mysterious script with assured, thoughtful direction, buoyed by a fine ensemble cast and crisp, sometimes remarkable cinematography.

Like its title character, Borgman is unique and hypnotic, leaving you with so many different feelings you won’t be quite sure which one is right.

1. The Nightmare (2015)

An effective scary movie is one that haunts your dreams long after the credits roll. It’s that kind of impact that most horror buffs are seeking, but even the most ardent genre fan will hope out loud that Rodney Ascher’s documentary The Nightmare doesn’t follow them to sleep.

Sleep paralysis is the phenomenon that inspired Wes Craven to write A Nightmare on Elm Street. It’s a clear creative root for Insidious, Borgman, and scores of other horror movies. But it isn’t fiction. It’s a sometimes nightly horror show real people have to live with. And dig this – it sounds like it might be contagious.

We spend a great deal of time watching horror movies, and we cannot remember an instance in our lives that we considered turning off a film for fear that we would dream about it later. Until now.