How much time do you need to smoke to get addicted?

No magic number: but an old statistic which I think holds is that if an individual smokes 7 or more cigarettes, they have a 90% chance of becoming dependent and a chronic smoker. There are rare individuals who really do smoke "socially," having 1-2 cigarettes at special occasions a few times a year, without developing dependence, but they are few and far between.