But the pop star and X Factor judge said she has struggled with just how much to reveal, since her struggles went further than anyone knew.
"I'm battling with internal thoughts on how honest I should be," Lovato said.
"Yes, I've been very honest, but if people really knew how dark and deep my struggles got -- not just with my eating disorder but with drugs and alcohol -- they'd be really shocked."
"I'll most likely end up saying everything," she said. "Maybe it'll help other people in the industry who are headed down the wrong path."
And in case anyone thinks she's referring to her fellow former Disney star, Miley Cyrus, Lovato assured Cyrus isn't who she has in mind.
"She's having fun and figuring out who she is, and this is the age when that happens," Lovato said, of Cyrus. "I think that she's doing her own thing. Good for her."