updated 10/01/2011 AT 12:00 PM ET
•originally published 10/01/2011 AT 3:40 PM ET
When Lovato, 19, worked through her eating disorder and other issues last year and entered treatment in October, Kardashian, 30, was there for her.
“I feel like there are some people that you’re friends with that talk to you on Twitter or text,” the Disney star tells Billboard.com. “But the people that are really there for me are the people that were there for me when I went into treatment.
“The people that were calling me while I was in there were Kim Kardashian and Selena Gomez,” adds Lovato. “Those two girls, they meant the world to me. They still do.”