But Lovato, of course, knows a lot about addiction.
She went to rehab a couple years ago and has been open since about her history of eating disorders and drug use.
"I wish more people would lose the stigma and treat addiction as the deadly and serious DISEASE that it is," Lovato wrote in response to Hoffman's death, adding:
"Drugs are not something to glamorize in pop music or film to portray as harmless recreational fun. ... It's very rare when people can actually predict their addiction and even then, you never know when too much is going to take their life or take a bad batch of whatever it is their using."
"This stuff is not something to mess with," she Tweets of drugs in general. "Why risk it? Addiction IS a disease. Please spread the word so we can take the taboo out of discussing this illness and raising awareness to people of all ages.
"RIP Philip Seymour Hoffman.. An INCREDIBLE artist who lost his life to this horrible disease.. May you rest peacefully and in complete serenity now that your pain is gone. God Bless..."
Bravo, Demi. We applaud this star for both battling her own disease and standing up for those who attempt to do the same. Even when they tragically fail.