In a video on her website, she thanked ファン for their support, and 発言しました she'd been on a "very difficult journey".
The 18-year-old ディズニー 星, つ星 quit a tour with the Jonas Brothers in November 2010 to get treatment for "emotional and physical issues".
She hasn't 発言しました why she entered rehab but in November a spokeswoman 発言しました she had a history of eating disorders.
In the video, Lovato 発言しました she had been treated for issues that "girls of all ages are dealing with".
'Darkest time'
"I hope to one 日 raise awareness of everything so that I can help people too, just like あなた guys helped me through this rough time," she said.
"I can't tell あなた how much light あなた guys brought into my life in probably the darkest time in my life.
"Without あなた guys I probably wouldn't be here today."
The teenager is a major 星, つ星 in America and dated US pop 星, つ星 Joe Jonas.
She also has her own show, Sonny With A Chance.
She released her debut album Don't Forget in 2008 and the follow-up Here We Go Again a 年 later.
When she quit the Jonas Brothers tour, she had been working on her third studio album, which was due to be released in 2011.
