Michael Douglas through his battle with throat cancer.
Her publicisist, Cece Yorke, released the following statement: "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."
"She's feeling great and looking forward to starting work this week on two upcoming films."
The Welsh actress was reportedly admitted to the Silver Hill psychiatric hospital last Wednesday, where she stayed for five days.
Michael Douglas underwent radiotherapy and chemotherapy for stage four throat cancer last year, before getting the all clear in January.