It was interesting to hear that when she made the movie, they didn't really have any research to draw on or a diagnosis for the character of Alex. They weren't even trying. Alex was merely drawn as a deranged jealous woman and motivated toward violence by her broken affair and a fictitious past that made this behaviour feasible.
Close brings up a great point that's always been in my periphery: The Crazy Antagonist. I've always hated movies and books that simply fall back on the villain being 'crazy.' Aside from the fact we now know it's incredibly dismissive of a person's genuine suffering, it's just too easy. Dare I say it's even lazy? I mean, you can play out almost any behaviour when you've got a loose canon adjective like 'crazy', can't you?
One thing about writers, we love to study the human animal. Some of the best writing advice I ever received was the simple question, Why? Why does your hero say that when it's not true? Why does she go down the spooky set of stairs when it's obviously dangerous? Motivation is the key to readers identifying and sticking with a character through any and all outlandish behaviours.
For instance, in the movie Pitch Perfect, the main character joins the a cappella club, not because she likes it, but because her father says he'll pay her way to California and DJ'ing if she gets involved with an on-campus club.
With The Crazy Antagonist, you get to skip that step. I much prefer a well motivated villain with wants and desires that conflict with the protagonist's to produces a genuine contest of wills. It raises the stakes and the story becomes more interesting (to me.) At the very least, if we're going to depict someone with mental illness, let's please stop making them the bad guy.
How about you? Do you buy into The Crazy Antagonist?