You gotta push past some douchiness, but Bret Easton Ellis has the best stuff to say about novels vs. screenplays and adapting fiction into movies.

Why Bret Easton Ellis doesn’t care how The Canyons is received

A screenplay is very utilitarian. It’s a blueprint for the movie, which is a collaborative thing. Your job is to give everyone the idea for the movie, hopefully have all the scenes in order, and have dialogue that moves the story forward. That’s bare-bones. Of course, then you can write a good script with good dialogue—it doesn’t all have to be expository. That really is your job as the screenwriter. I would never write a screenplay the way that I write a novel. It’s pretty simple, because it really is all about structure. The director is going to interpret it in a certain way, and the actors are vital collaborators, because they will bring their own essence to each role. The editor will change things, and you might not get that location, so that changes the feel for the scene you wrote that took place in an exterior but because of budget restraints in now an interior.

Comics are very much the same way.

Sidenote: I once read BEE’s “American Psycho” in one sitting, while riding a train from Pittsburgh to Washington, DC. I don’t recommend that.