So much for patient confidentiality! Catherine Zeta-Jones wanted to keep her treatment for bipolar disorder under wraps before she was “outed” by a fellow patient, her hubby, Michael Douglas, told Oprah Winfrey yesterday. “Catherine is being quite open about it because she was outed,” he said. “She went to go get some help, and some other patient, probably, in there said, ‘Hey, you won’t believe who’s in here now.’ And so once that happened, I think she felt [it] best to kind of get out the story.” Douglas said Zeta-Jones’ struggle followed many other recent family trials and tribulations. Trying to put some light on the situation, he noted, “My oldest son is in federal prison, my ex-wife is suing me and I got cancer. It’s kind of hard for the wife to say, ‘I’m depressed.’ ” But he said, “I’m so proud of her for analyzing it and taking care of it . . . She’s relieved that she has a much better understanding.”