Demi Lovato has revealed some shocking details about her 2018 near-fatal overdose, saying for the first time that she suffered three strokes and a heart attack.

The 28-year-old "Confident" singer made her comments in an upcoming four-part documentary about her life, titled Demi Lovato: Dancing With the Devil, which is set to premiere on YouTube on March 23. A trailer was made public on Wednesday, Feb. 17, and also contains an excerpt of Lovato's new song by the same name.