(Cover) - EN Showbiz - Demi Lovato has bipolar, saying her depression stemmed from a very young age.

The 18-year-old actress-and-singer checked into a treatment facility at the beginning of November last year to receive care for emotional and physical issues. She left the centre three months ago, and in an interview with People she has revealed she discovered she has bipolar during her stay at the centre. The star, who also received care for bulimia, anorexia and self-mutilation, says having a diagnosis was a big help as she had suffered depression from a very young age.

"I never found out until I went into treatment that I was bipolar," she explained. "Looking back, it makes sense."

The star never realised her behaviour was unusual, although now when she looks back she realises her bursts of energy were out of the ordinary. The talented musician says she would often stay up all night working.

"There were times when I was so manic, I was writing seven songs in one night and I'd be up until 5:30 in the morning," she revealed.

Demi feels much better now she has received treatment. She now hopes to use her positive outlook and strength of character to help those who have endured similar problems to her.

I feel like I am in control now where my whole life I wasn't in control," she said. "What's important for me now is to help others. (C) Cover Media