My heart stopped when they said she overdosed, but thankfully the Sylvia Skype session followed.
I will say that I laughed out loud when Sylvia was like, "You know me, I'm Sylvia!" after Karissa darted out of the Intervention. Of course we, as fans, know Sylvia... But it's not like she's a household name.
(They did hug immediately afterward, so maybe Karissa is more familiar with the show than I'm giving her credit for.)