Were there signs Catherine Zeta-Jones had bipolar disorder?

Apr 14, 2011 at 9:57 a.m. ET

Fans were shocked when actress Catherine Zeta-Jones checked into a facility to treat her bipolar II disorder, however, she had hinted that she struggled with depression and had difficulty dealing with husband Michael Douglas' cancer battle.

Catherine Zeta-Jones and Michael Douglas

Catherine Zeta-Jones checked into a treatment facility for a five-day stay to treat her bipolar II disorder "after dealing with the stress of the past year," however, the Oscar-winning actress had given hints of her private struggle with depression.

According to experts, bipolar disorder causes cycles of high and low moods with episodes of depression. Other celebrities who struggle with it include Carrie Fisher, who told USA Today, "A manic phase is not predictable. The last time, I hacked off my hair, got a tattoo, and wanted to convert to Judaism." Britney Spears is another celebrity to also struggle with bipolar disorder.

Zeta-Jones had hinted at her disorder when talking to the Sunday Times. "I'm lucky... But that's not to say I don't get down on myself. I try and stay positive, being negative isn't good for my personality. I don't just bring myself down, I bring everyone around me down. It's like a dark cloud, 'Uh oh, here we go,' and I have to snap out of it."

Some also point to the rambling speech she gave at last year's Tony Awards as a sign that something was wrong. Zeta-Jones, 41, won the award for Best Actress in a Musical. She talked on and on, ignoring the music, and ended her speech by saying, "See that man there? He's a movie star and I get to sleep with him every night." She later said she regretted saying that, calling it "crass," however, some point out that this could have been a hypo-manic state in which behavior is irrational.

The actress has undoubtedly had a stressful year, dealing with her husband Michael Douglas' battle with cancer. Many experts say that stress can trigger the mood swings that go along with bipolar depression. A family source said that she "had a lot of trouble coping. She was chain-smoking and drinking" and had "more sleepless nights than you could possibly know."

It sounds like Catherine Zeta-Jones has taken all the right steps to getting healthy and her opening up about this will undoubtedly help those also struggling with bipolar disorder.