The addiction
I'm not so sure about that. I think both are intertwined. The guy who was ANS's manager during the Playboy and Guess era (who has a book on ANS coming out this week!) said she was perfectly normal, lucid, non-addicted during that time period and then Howard came into her life. Of course, she probably used/abused drugs and alcohol all her life, but the addiction followed Howard entering her life. Use and addiction are two separate things. IMHO HKS was instrumental in the initiation of her addiction, if not very closely linked.