In a video on her website, she thanked fans for their support, and said she'd been on a "very difficult journey".
The 18-year-old Disney star quit a tour with the Jonas Brothers in November 2010 to get treatment for "emotional and physical issues".
She hasn't said why she entered rehab but in November a spokeswoman said she had a history of eating disorders.
In the video, Lovato said she had been treated for issues that "girls of all ages are dealing with".
'Darkest time'
"I hope to one day raise awareness of everything so that I can help people too, just like you guys helped me through this rough time," she said.
"I can't tell you how much light you guys brought into my life in probably the darkest time in my life.
"Without you guys I probably wouldn't be here today."
The teenager is a major star in America and dated US pop star 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 year 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.
It's the most beautiful, homey-feeling house.I love it.The pool has a water slide, which is really cool.'Demi told MTV:'I'm turning 18, yeah
I would love to.. I don't know!I would love to just have fun with my friends.I don't get to see my friends a lot, so a lot of my friends are coming out[to visit].My family flew out.I'm just having a good time with them.I have everything I could possibly want.Everyone's asking me,'What do you want for you birthday?'
I'm like,'I don't know!Handbags?'Like,I have everything I could want.I'm just thankful.'
She was driving through LA last week when she got in a fender bender. The cause? According to Demi it was because she was tired. She said she hadn't slept well, and because of still being half asleep, wrecked her car.
But not to worry! Demi is fine and told all her fans on Twitter that she was OK and thanked them for their concern.
Lucky for her, Demi's accident was nothing more than a scare, but it is a good reminder that we need to be working with all 5 senses when behind the wheel.
9.She never lies
8.She wears pretty clothes
7.She's on the new show sonny with a chance
6. She has lots of great pictures
5.She's in Camp Rock
4.She knows how to play guiatar
3.She's also friends with Selena Gomez,and Miley Cyrus
2.She's The funniest person i've ever seen
1.SHE'S MY FAVORITE STAR!!!!!!!!!!!!!!!
Thanks For Reading it! And remember just like demi never tell a lie!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
OK guys we all know Demi Lovato has a ton of talent and we all love her so we need to come up with a new way to get more Demi Lovato fans on fanpop or buy her CD. Her BFF Selena Gomez is asking her fans to buy and check out the Demi Lovato CD so that's what we need to do. Demi Lovato is a great romodle for children plus her and The Jonas Brothers and Selena Gomez right now seem to be 3 of about 10 Disney Channel stars who have not done anything that could get them in trouble with the law so guys ask your friends to look up to Demi Lovato!!!!!!!!!!!!!!!!!!!!!!!!!!!!
