The 18-year-old Camp Rock star has checked into a treatment facility to, according to a rep for the actress, deal with issues that have evidently been plaguing her for awhile.
"She was in Peru and just couldn't continue," a source tells E! News.
"Demi Lovato left her tour early this weekend in order to seek medical treatment for emotional and physical issues she has dealt with for some time," a rep for Lovato said in a statement.
"Demi has decided to take personal responsibility for her actions and seek help. She is doing just that. She regrets not being able to finish her tour, but is looking forward to getting back to work in the near future."
The source tells E! News that Lovato's exhausting work schedule—-performing on the Jonases' summer tour, promoting Camp Rock 2 and then going abroad for the international leg of the tour—"overwhelmed" and ultimately took its toll on her.
Lovato reinstated her Twitter account about a week after initially pulling the plug in September, but her account went dark again on Saturday.
Whatever is troubling the teen, we certainly hope she feels better soon!
—Additional reporting by Ken Baker
(Originally published Nov. 1, 2010, at 6: 25 p.m. PT)