When I was in Vietnam, I took a photo of a woman who was addicted to betel nuts. They are addictive little nuts that give you a lot of energy; my uncle said that 95% of all truck drivers here depend on them for their trips. Well I googled "addictive nut taiwan", and the first article that came up was about "Betel-Nut Beauties", girls with stands on the sides of the highways who sell drinks, cigarettes, and betel nuts. It's a pretty fascinating sub-culture, read the article if you're interested.