https://ihorror.com/what-inspired-a-nightmare-on-elm-street-true-story/
Straight from Craven himself:
“I’d read an article in the ‘L.A. Times’ about a… young son [who] was having very disturbing nightmares. He told his parents he was afraid that if he slept, the thing chasing him would get him, so he tried to stay awake for days at a time. When he finally fell asleep… they heard screams in the middle of the night. By the time they got to him, he was dead. He died in the middle of a nightmare. Here was a youngster having a vision of a horror that everyone older was denying. That became the central line of ‘Nightmare on Elm Street.’”