Katy Perry addresses Las Vegas Massacre in concert There is video footage for this Katy Perry story; click HERE. Katy Perry SHARE RELATED CONTENT Demi Lovato’s alleged drug dealer speaks on the overdose. Drake visits 11-year-old awaiting heart surgery. Emergency landing for Post malone! How much $ does Britney Spears have to give K-fed monthly? So, we think we know what Demi Lovato overdosed on. Ellen invites Demi Lovato to appear on her show post rehab.