Catherine Zeta-Jones, who has stood by her husband, Michael Douglas, during his battle with cancer of the tongue, announced Wednesday, via a rep, that she's entered a facility to be 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 for a brief stay to treat her Bipolar II disorder," a rep for the 41-year-old actress said, People reports. "She's feeling great and looking forward to starting work this week on her two upcoming films."