Actress Catherine Zeta-Jones checked herself into a mental hospital to treat Bipolar II Disorder, her representative tells People magazine.

Zeta-Jones made the decision to enter treatment following her husband Michael Douglas' battle with cancer.

"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," the rep said in a statement. "She's feeling great and looking forward to starting work this week on her two upcoming films."

The 41-year-old actress spent about five days in the facility, People reports.

Bipolar disorder is a mental illness that affects an estimated 6 million Americans. It is traditionally marked by elevated moods, followed by alternating periods of depression. Those afflicted with bipolar II tend to have bouts of depression, where mood swings last longer and the elevated moods are less dramatic.

In 2010, Zeta-Jones' stepson, Cameron Douglas, was sentenced to five years in prison for drug-related charges, and only four months later, her actor husband was diagnosed with cancer. In between the devastating events, Michael Douglas was also sued by his ex-wife, Diandra, who claimed she was entitled to 50 percent of the profits from his film 'Wall Street: Money Never Sleeps.'

"There’s no question it's been a stressful year," a friend of the actress told the magazine. "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."

Douglas, 66, recently announced that he is free of cancer of six months of chemotherapy and radiation.

Zeta-Jones and Douglas have two children, Dylan, 10 and Carys, 7.