It is argued that gateway drugs open the door and progressively leads one to harder drugs. We at the Meth Action Coalition teach this to students:
A gateway drug is:
§ Any drug use that exposes the user to a different circle of friends. We do what our friends do.
§ Tolerance to one drug stimulates desire for a bigger high
§ While high on one drug, impaired judgment causes the user to try another drug.
§ Drug use that lowers inhibition to illegal activity.
§ The most common gateway drugs are cigarettes, alcohol and marijuana.