Aren't roughly 10% of people alcoholics? And I imagine that percentage is similar across the world, despite widely varying cultures.

Edit: I recall reading somewhere that 25% of people who use heroin develop addictions. Let's say that we are as successful at developing a culture of heroin use as we have been at developing a culture of alcohol use so that we can reduce addiction to 10%. It seems likely to me that any such culture would more than triple the number of people using heroin, so the overall effect is probably to increase the number of addicts.