Demi Lovato discovered who her true friends were when she checked into rehab in 2010 and only four people contacted her.
Demi Lovato claims rehab showed her who her real friends were.
The 'X Factor' USA judge says checking in to a treatment facility to help her overcome her struggles with bulimia and self-harming in 2010 was a life-changing move, especially because it proved who actually cared about her.
She told Company magazine: ''A couple of months before I went to rehab, I had a birthday party, and there were a couple of hundred people there. It was full of people who I considered my closest friends.
''When I turned my phone on after being in rehab for three months, I expected lots of text messages and phone calls. I had four texts. That was a wake-up call.''
The 20-year-old singer - who used to be friends with her fellow Disney stars Miley Cyrus and Selena Gomez - has cut most of her old pals out of her life and now only has a small support group of people she can rely on.
Demi added: ''I don't have loads of friends. I used to, but then I realized, do any of them actually care?
''Now I have people who, if I break my leg in the middle of the night, will come to the hospital with me. Or they'll answer the phone at 4 a.m. if I need them.''