What is meant by gateway substances? What is one example of a gateway substance? What is wrong with assuming that use of a gateway substance causes increased use of other substances?

What will be an ideal response?

A substance (e.g., cigarettes) that is used before illicit substances AND use of which is associated with increased likelihood of later use of illicit substances. Assuming a person is generally more likely to engage in deviant or problem behavior, the apparent gateway substance might just be the easiest thing for a young person to start with, so it is most likely to be the first. Bonus: discussion of whether preventing or delaying cigarette smoking would reduce later use of marijuana or other substances.