Catherine Zeta-Jones Treated For Bipolar II Disorder

'After dealing with the stress of the past year, Catherine made the decision to check in to a mental health facility,' actress' rep says.

Catherine Zeta-Jones surprised everyone on Wednesday when she went public with her battle with bipolar II disorder. The star's rep confirmed that the Hollywood A-lister spent about five days in an unidentified facility to deal with the illness.

"After dealing with the stress of the past year, Catherine made the decision to check in to a mental health facility for a brief stay to treat her bipolar II disorder," her rep said in a statement to People.com. "She's feeling great and looking forward to starting work this week on her two upcoming films."

Zeta-Jones and her husband, Michael Douglas, certainly have had a stressful year. Douglas underwent treatment for throat cancer last year, and in January, he appeared on the "Today" show to discuss his medical scare and tell fans that he is now cancer free.

"There's no question it's been a stressful year," a friend of Zeta-Jones said. "Catherine has had to deal with Michael's illness and that's been hard. She went in for a few days because she's about to start working and wanted to make sure she's in top form, which she is."

Bipolar II disorder is a form of depression characterized by episodes of major depression alternating with periods of elevated highs, also known as hypermania. Often the disorder is triggered by periods of stress and can lead to a depression that includes mood swings. Bipolar II disorder differs from bipolar I disorder in that the "up" moods never reach full-on mania, according to WebMD.

Douglas and Zeta-Jones appeared at the Golden Globes earlier this year, where he commented on his recent medical challenges. "There's got to be an easier way to get a standing ovation," Douglas joked about his warm reception. "Thank you all very much. I'm really very, very happy to be here tonight," he added, as Zeta-Jones looked on from the audience.