The Skyscraper singer sought professional help for a long-term eating disorder and emotional issues earlier this year.
“I think I was out of tears at that point… [Selena] called me and she was crying, she was like, ‘Hello.’ I’m like, ‘Why are you crying? I’m the one in treatment – like, I should be crying’,” Demi, 19, told Access Hollywood.
“She’s definitely one of my closest friends and no matter what we’ll always be close as sisters. We met 12 years ago, that’s more than half of my life.”
She admitted that at the height of her illness, she was making herself sick up to five times a day.
“I think at the worst it was a little more than that,” she said. “I was just so sick. I thought that orange juice was going to make me fat.”
Now fighting fit and with her new album, Unbroken, riding high in the charts she said that she feels better than ever.
“I feel amazing. I feel really happy and healthy. Life is beautiful and I can’t complain.”