In a video on her website, she thanked شائقین for their support, and کہا she'd been on a "very difficult journey".
The 18-year-old Disney سٹار, ستارہ quit a tour with the Jonas Brothers in November 2010 to get treatment for "emotional and physical issues".
She hasn't کہا why she entered rehab but in November a spokeswoman کہا she had a history of eating disorders.
In the video, Lovato کہا she had been treated for issues that "girls of all ages are dealing with".
'Darkest time'
"I hope to one دن raise awareness of everything so that I can help people too, just like آپ guys helped me through this rough time," she said.
"I can't tell آپ how much light آپ guys brought into my life in probably the darkest time in my life.
"Without آپ guys I probably wouldn't be here today."
The teenager is a major سٹار, ستارہ in America and dated US pop سٹار, ستارہ 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 سال 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.
