Demi Lovato found out she has bipolar disorder while in rehab

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Demi Lovato is speaking out about her personal troubles in hopes of helping other teens.

Demi Lovato, who has admitted to cutting, overeating and starving herself as far back as elementary school, didn't know the name for some of her problems until suffering a breakdown last fall.

"I never found out until I went into treatment that I was bipolar," she told People magazine.

"Looking back it makes sense," the 18-year-old said. "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."

Bipolar disorder is characterized by alternating periods of extreme highs and extreme lows.

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Lovato knew she was "depressed from a very young age," but it took an intervention to get her to seek medical help.

And after three months in an Illinois rehab center, Lovato said she feels "like I am in control now where my whole life I wasn't in control."

Knowing first-hand how therapy can radically change a person's life, it's no surprise that the singer-actress has vocalized her support for Catherine Zeta-Jones, who also recently sought treatment for bipolar disorder.

"I don't know Catherine Zeta-Jones personally but what she has decided to do it SO brave [sic]. And SO difficult but worth it," she tweeted last week. "I'm proud of her."

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