AceShowbiz - Faye Dunaway has opened up about her infamous bad behavior on movie sets. In an upcoming documentary film, "The Case for Christ" actress blamed bipolar disorder for her worrying actions.

In the movie, the 83-year-old explains the reason why she had bad behavior on her movie sets. Noting that she doesn't want to dismiss her actions, the "Bonnie and Clyde" actress says, "Throughout my career, people know there were tough times."

Faye goes on to state, "I don't mean to make an excuse about it. I'm responsible for my actions but this is what I came to understand, was the reason for them. It's something you need to be aware of, you need to try and do the right thing to take care of it."

In the same documentary film, Faye further declares that her condition that she called a "biological physical" reality is a "part of my makeup." "The Bye Bye Man" actress also voices her gratitude that there is available medication for her condition, adding, "The medication is crucial."

Elsewhere in the movie, Faye's son Liam, whom she has with a late photographer named Terry O'Neill, talks about his mother hitting "rock bottom" a couple of years ago. Liam shares, "So I kind of got to the point where I said, 'Hey listen, let's get you to this clinic in Boston.' " He continues, "She went to lectures and classes and they got her on the right stuff and she came out like a whole new person."

Previously, Faye's co-workers revealed what it was like to do a project with her. One in particular was Roman Polanski, the director of "Chinatown". Roman deemed her a "gigantic pain in the a**" for her behavior. Though so, the filmmaker also praised her. He said that he had "never known an actress to take work as seriously as she does."

In the meantime, fellow actress Bette Davis thought that Faye was the worst person she had ever worked with. During a chat with Johnny Carson back in 1988, Bette described Faye as "totally impossible," "uncooperative" and "very unprofessional."