43-year-old actress Catherine Zeta Jones has reportedly checked in a medical facility to seek help for her Bipolar II disorder.

Not a lot of people would have thought that "The Mask of Zorro" actress is battling bipolar disorder. The Academy Award winner reportedly checked in a medical facility on Monday for a complete 30-day program to treat her bipolar II.

According to celebrity news website TMZ, sources close to Catherine said that the treatment was proactive and it was just for "maintenance." Jones first sought help back in 2011. At that time, her spokesperson said that the actress "made the decision to check in to a mental health facility for a brief stay to treat her Bipolar II disorder."

In 2011, she stayed for five days at the detox center in New Canaan, Connecticut. Meanwhile, she just walked the red carpet on April 22 with her husband Michael Douglas at the 40th Anniversary Chaplin Award Gala at the Lincoln Center.

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

Catherine has been dealing with a lot of emotional stress since her husband battled stage four throat cancer in 2010. The actress first showed signs that she was struggling when she broke down in public at the Ryder Cup Welcome to Wales concert at the Cardiff Millennium Stadium.

"It's been the most difficult year of her life. She's been through hell! The pressure has been almost unbearable," a family source said.

"Catherine had a lot of trouble coping. She was chain-smoking and drinking. It was tearing Catherine apart to see such a vital man as Michael in such a weakened state. I think she was crumbling," the source added.