Mariah Carey Opens up about her Battle with Bipolar Disorder in People Magazine

In this week’s PEOPLE cover story, Mariah Carey reveals for the first time her battle with bipolar disorder.

Although she was first diagnosed in 2001 (when she was hospitalized for a physical and mental breakdown), “I didn’t want to believe it,” the superstar singer-songwriter tells PEOPLE editor in chief Jess Cagle.

Carey says she finally sought treatment recently after “the hardest couple of years I’ve been through” — years of professional upheaval, an E! reality show and romantic drama.

“Until recently I lived in denial and isolation and in constant fear someone would expose me,” she says. “It was too heavy a burden to carry and I simply couldn’t do that anymore. 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.”

One of the most successful singers of all time, with 18 No. 1 hits and more than 200 million records sold, Carey spent many of her years in the spotlight suffering in silence.

She is now in therapy and taking medication for bipolar II disorder, which involves periods of depression as well as hypomania (less severe than the mania associated with bipolar I disorder, but can still cause irritability, sleeplessness and hyperactivity).

For more on Mariah Carey and her battle with bipolar disorder, dealing with fame and raising twins, pick up the latest issue of PEOPLE, on newsstands Friday. For mental health support, contact the Depression and Bipolar Support Alliance at dbsalliance.org.