I'd say that once the threshold has been crossed into addiction, whether or not the personality is present is moot. At bare minimum it'd be like having a choice between swallowing cyanide or playing Russian Roulette. Either way, the odds are stacked against you.

Best way I ever heard it described was by an old-timer at an AA meeting: "If you take a cucumber, put it in vinegar, and leave it there long enough, it becomes a pickle. That pickle will never be a cucumber again."

Hope that helps. :)