Huh? I know people say he's a coke fiend, but is there any suggestion that he actually has any addictions? Or is that just a throw-away line?
There's been a lot of people who worked behind the scenes that have similar tales of Vince being coked out of his mind a lot of the time, not to mention the stories of his legendary work ethic/schedule that would be nearly impossible to maintain as long as he has without some kind of chemical assistance. Also the tons of examples of Vince exhibiting inappropriate/weird behavior both on and off screen. In short, there's never been any conclusive proof but there seems to be enough circumstantial evidence to assume he's not just getting by on Red Bulls.
"Erratic behaviour" is often used as a code word.
Both Ring of Hell and Sex, Lies and Headlocks made explicit references to Vince's coke use based on the accounts of those who have worked with him.