Demi Lovato at Top of Her Game on GMA (watch!) 1

Demi Lovato has come a long way since her breakdown in 2010. She demonstrated that she’s at the top of her game with a rousing performance in its summer concert series on ABC’s “Good Morning America.”

Lovato, 19, another former Disney star who is trying to transition to an adult career, talked openly about her struggle with eating disorders and depression.

She says being diagnosed with a bi-polar disorder during her stint in rehab two years ago, actually was a relief.

“I would stay up until like five in the morning just playing guitar and my parents would wake up for work and they’d be like, ‘What are you doing?'”

“And finally when I got diagnosed I was like, ‘Oh, cool, I’m not crazy, it’s something. It’s a disease,'” she explained.

Although most celebrities try to keep their problems under wraps, Lovato said she decided to let it all hang out, to inspire others. “That’s what being a role model is about,” Lovato said during the interview.

Lovato appeared on the show to promote her new album Unbroken, her third studio album. Lovato says the sound is “more mature” and ” more R&B/pop oriented, with influences by Rihanna and Keri Hilson.

Lovato was a surprise pick to fill a judge’s seat on Simon Cowell’s music talent show “The X Factor.” She joined Britney Spears and says so far so good.

“It’s going so good. I’m having so much fun. It’s amazing,” Lovato said. “We tease each other all day long.”

Check out her interview below and watch her perform one of her songs.