There is no easy answer to this common question. If and how quickly you become addicted to a drug depends on many factors, including your biology (your genes, for example), age, gender, environment, and interactions among these factors. Vast differences characterize individual sensitivity to various drugs and to addiction vulnerability. While one person may use a drug one or many times and suffer no ill effects, another person may overdose with first use, or become addicted after a few uses. There is no way of knowing in advance how quickly you will become addicted—but there are some clues, one important one being whether you have a family history of addiction.