Philip Seymour Hoffman’s tragic death sparked a conversation about celebrities and their personal struggles with addiction.

Hoffman was found dead of an apparent heroin overdose on Sunday (Feb. 2) in New York City after years of battling his addictions. He struggled with substance abuse in his twenties, but remained sober for over two decades before relapsing last year.Hoffman checked into rehab in May 2013 to deal with abuse of prescription pills and heroin.

Demi Lovato, who went to rehab in 2010, spoke out shortly after hearing of Hoffman’s death, telling “Extra,” “People don’t take it as seriously as it really is, it’s a mental illness and it’s a disease … There’s no pill that’s gonna change it. People need to have compassion for it.”

“Being a former addict looking at it as I had a choice, because at some point in my disease I didn’t, I physically and emotionally couldn’t live without it,” Lovato, who struggled with a cocaine addiction, continued, “that was my medicine to my pain.”

Here are other stars who’ve opened up about their addictions: Click here to see slide show of celeberties and their stories…