Faye Dunaway Reveals Her Past Bad Behavior Was Due to Undiagnosed Bipolar Disorder, Says Taking 'Medication Is Crucial'

Actress Faye Dunaway will open up about her struggle with bipolar disorder in the upcoming HBO documentary Faye.

The star was infamous for her poor behavior and acting out on movie sets, something she attributed to her mental health condition, which she wasn't aware of during the height of her days in Hollywood.

"Throughout my career, people know there were tough times. 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," the Oscar winner, 83, explained of the diagnosis. "It’s something you need to be aware of, you need to try and do the right thing to take care of it."

Dunaway said the condition is "part of my makeup" and noted that "the medication is crucial" to living a normal life.

Her son Liam — whom she shares with late ex-husband Terry O’Neill — revealed that the movie icon finally went to get help when she "hit rock bottom" a few years ago.

"So I kind of got to the point where I said, 'Hey listen, let’s get you to this clinic in Boston,'" he recalled. "She went to lectures and classes and they got her on the right stuff and she came out like a whole new person."

One of her most notable spats was with Chinatown director Roman Polanski, 90, who told a reporter years ago that she was a "gigantic pain in the a-- ... I tell you, she is a maniac."

Never miss a story — sign up for the OK! newsletter to stay up-to-date on the best of what OK! has to offer. It’s gossip too good to wait for!

She also had a tiff with Bette Davis, as on an episode of Johnny Carson's talk show, Davis called Dunaway one of the worst people she's ever worked with.

"Everybody will tell you exactly the same thing. She's just totally impossible," she insisted. "I don't think we have the time to go into all the reasons."

"She's just uncooperative," Davis added. "Very unprofessional."

In Dunaway's memoir, she responded to Davis' harsh words.

"Watching her, all I could think of was that she seemed like someone caught in a death throe, a final scream against a fate over which no one has control," the star wrote. "I was just the target of her blind rage at the one sin Hollywood never forgives in its leading ladies: growing old."

Page Six reported on the documentary, which debuts on Saturday, July 13.