'Heart Attack' beauty Demi Lovato has revealed that her stint in rehab showed her who her real friends are in the entertainment industry and she only had a small number of peers call to make sure she was alright. 

During a revealing new interview with Access Hollywood, the superstar explained that seeking treatment for bipolar disorder among other emotional issues was tough, but she quickly learned which of her contemporaries she could truly call friends:

"I lost friends when I came out of treatment because I realised who wasn't there for me. I can list about five or six people that called me and made sure that I was okay."

"Selena was there for me. She called me crying and I was like, 'Why are you crying?' Taylor Swift sent me an e-mail saying, 'Hey, I don't know if you have a phone right now, but are you okay? Miley, too. But there weren't many more than that."

In the same interview, Lovato admitted that she was previously addicted to cocaine and struggled to go for more than an hour without taking a hit of it: "Something I’ve never talked about before, but with my drug use I could hide it to where I would sneak drugs. I couldn’t go without 30 minutes to an hour without cocaine and I would bring it on airplanes. I would smuggle it basically and just wait until everyone in first class would go to sleep and I would do it right there."