Conversation so far:
Was Nikki Sixx in a relationship?
Nikki Sixx was engaged to Denise Vanity Matthews in 1987.
Did Nikki Sixx ever get married?
From May 1989 to November 1996, Nikki Sixx was married to his first wife, Playboy Playmate Brandi Brandt.
Did Denise Vanity Matthews ever play in a band?
Vanity was the lead singer of the female trio Vanity 6.
Was Denise Vanity Matthews a groupie?

Question: Was she a drug addict?
Self-contained rewrite: Was Denise Vanity Matthews a drug addict?