Is it possible to be addicted after just one cigarette?

Not exactly: This is a trick question. If a person inhales from 1 cigarette and then stops, the question of being addicted is moot. That is, addiction (or substance dependence) is defined as "a maladaptive pattern of substance use." there is no pattern in a single instance of smoking a cigarette. But, 10% percent of youth who become hooked on cigarettes are addicted within two days of their first cigarette.