For the first time since entering rehab last fall, Demi Lovato is opening up about the problems that led her to seek treatment in the first place.

The Disney starlet, whose rep had previously said she was getting help for "emotional and physical issues," revealed in the May issue of Seventeen that she had been struggling with cutting, an eating disorder and depression for years.

But Lovato's troubles came to a head in October, when she punched Alex Welch, a dancer on her international tour with the Jonas Brothers.

"Lashing out was my cry for help," the 18-year-old told Seventeen. "Wow, who was...