Demi Lovato has spoken out on the recent death of Glee star Cory Monteith, who was found dead Saturday from a heroin and alcohol overdose. Lovato, who has also struggled with substance abuse, hopes that the actor's death will help raise awareness of the issue.People. "He didn't choose to die. It was the disease. It can creep up on you at any moment. It only takes one moment of relapse to potentially die. It's really scary, but I'm really hoping that from this, people are able to see this is a very, very, very dangerous disease."Lovato entered a treatment facility for "emotional and physical issues" in late 2010, but didn't open up about her substance abuse until more than a year later. "Promoters gave me drugs and alcohol in restaurants or clubs. They wanted me to come back so I would be seen there. ... Being a celebrity can be dangerous. Nobody says 'no.' That's why so many end up overdosing and dying. It could definitely have happened to me," Lovato said at the time.Lea Michele. "The main person in my thoughts is Lea," Lovato said. "I am praying for her so hard and I love her so much. I'm wishing her a lot of strength right now."