In the scene at the party someone is shown jumping on a trampoline wearing a Ronald Reagan mask. This is taken from a photo of the journalist Hunter S. Thompson wearing a Reagan mask while he’s jumping on a trampoline.
During conversations with his therapist, Donnie refers to the TV show Married with Children and - more specifically, Christina Applegate. The script orginally called for Donnie’s fantasies to be centered around Alyssa Milano. This had to be changed when Richard Kelly was denied the legal rights to reference Milano in this context.
In the theater scene, Richard Kelly originally intended to have Donnie and Gretchen going to see C.H.U.D. However, there were problems with researching exactly who owned the rights to that movie, so Sam Raimi came to the rescue by allowing the film to use and distort footage from The Evil Dead free of charge.
Oddly enough, Noah Wyle’s character, Professor Kenneth Monnitoff, is seen eating hard candy in some scenes because Wyle simply decided his character would be diabetic.
