10 True Ghost Stories That Inspired Horror Films

Yes, the grandaddy of all spooky ghost stories actually has a grounding in reality - so now you can be doubly scared of the infamous horror film that has induced vomit and fainting fits for the past 30 years. You're welcome.

Inspired by the very real exorcisms of 'Ronald Doe', the representation of Regan and her horrific experiences weren't far off what the young Maryland boy suffered during the 1940s. It was apparently so bad that every written account of the events excludes his real name, instead referred to only as Ronald to preserve his identity - though he's now grown up as well as old, and has lived a happy and normal life in the aftermath of his ordeal.

Over 30 exorcism where performed on the boy, with no other medical explanations available for his bizarre symptoms at the time. It's believed that Ronald used a Ouija board in an attempt to contact his recently deceased aunt, and that's what allowed a paranormal entity to take control of his body.

The attending priests and reverends that treated the boy kept detailed diaries, writing of furniture moving by itself and Ronald speaking in a strange, guttural voice. He possessed the strength to break his treater's nose, and words appeared on his body with no cause, including the letter X which is believed to represent 10 - the amount of demons trying to take control of his body.

The Exorcist we know and love obviously exaggerates Ronald's experience to come degree, but to know that there's a shred of truth to Regan's ordeal is definitely not what we wanted to hear anytime soon. Keep your crucifixes at the ready.