Sharon Osbourne has been battling depression for 16 years.
'The Talk' host made the confession to her shocked co-stars on the CBS panel show while the group discussed comedian Wayne Brady's admission that he has struggled with the disorder.
The 62-year-old star revealed she too was battling depression and had been taking medication for 16 years to help her cope.
Her co-host Aisha Tyler, responded: "You never talked about that!"
Sharon replied: "Nobody ever asked!"
She added of her struggle: "Some days are better than others, and some days you feel like you just want to pull the sheets over your head and just stay in that bed and not do a damn thing - except rot."
Sharon - who is married to Black Sabbath rocker Ozzy Osbourne - was also diagnosed with colon cancer in 2002 and, after being given the all clear, underwent a double mastectomy in 2012 amid fears she could develop breast cancer.
Her husband, 65, recently spoke of his fear of losing his wife and shared his horror at watching her suffer violent seizures.
He said: "Sharon is the strongest woman I know. When I saw the scans of the colon, I thought, 'No way'. The cancer was so aggressive.
"She had three chemotherapies a month and after nine months the side-effects got worse and worse.
"She was having seizures - she was like The Exorcist, bouncing around the bed. I thought I was going to lose her.
"I thought it was all going to be too much for her. Then at the end of the nine months the doctor said, 'She's going to need nine months to get over the chemotherapy'. Her response was, I'm cancer free, great. I'm going shopping'."
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