April 11 (UPI) -- Mariah Carey is sharing her struggle with bipolar disorder for the first time.
The 49-year-old singer went public with her bipolar II diagnosis in the April 23 issue of People after years of living in "denial and isolation."
"Until recently I lived in denial and isolation and in constant fear someone would expose me," Carey told the magazine.
"It was too heavy a burden to carry and I simply couldn't do that anymore," she said. "I sought and received treatment, I put positive people around me and I got back to doing what I love -- writing songs and making music."
Carey was first diagnosed in 2001 during her hospitalization for a physical and mental breakdown. Bipolar II disorder is characterized by hypomania, which is less severe than mania with bipolar I disorder, and periods of depression.
"For a long time I thought I had a severe sleep disorder," Carey recalled. "I was irritable and in constant fear of letting people down. It turns out that I was experiencing a form of mania. Eventually I would just hit a wall."
The "I Don't" singer is now in therapy and taking medication to manage her condition.
"I'm just in a really good place now," she said. "[Bipolar disorder] does not have to define you and I refuse to allow it to define me or control me."
Carey said in an Instagram post Wednesday that she's "grateful to be sharing this part of [her] journey" with fans. Many voiced their support for the star in the comments, with one person writing, "Thank you for sharing this with the world. You show me what strength is everyday."