Mariah Carey has revealed her secret 17-year battle with bipolar disorder after becoming terrified she would be “exposed” by someone else.

The iconic singer has been battling with the mental health condition since being diagnosed in 2001 following a mental and physical breakdown, and said the last couple of years have been her hardest yet.

“Until recently I lived in denial and isolation and in constant fear someone would expose me,”

she told People magazine.

“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.”

Mariah, 48, is now on medication and has therapy after battling ‘manic’ insomnia that was characterized by non-stop working – until her energy would completely run out.

“For a long time I thought I had a severe sleep disorder, but it wasn’t normal insomnia and I wasn’t lying awake counting sheep,” she continued.

“I was working and working and working … I was irritable and in constant fear of letting people down. It turns out that I was experiencing a form of mania.”

As a result of her treatment, Mariah has cancelled her upcoming work commitments.