According to the National Institute on Drug Abuse (NIDA), by the time kids are in the 12th grade:
Marijuana, cigarettes and alcohol are the “gateway drugs” of our society today. When young people experiment with cigarettes, alcohol and marijuana, it often opens doors or “gateways” to stronger, more dangerous drugs and to risky situations where these drugs are readily available.
Because of their accessibility, gateway drugs are often introduced to young people by their older siblings, peers and even some parents. Regardless of the source, one point is clear – when a person tries one drug, statistics show that he/she will try another drug and that the other drug will be stronger, more powerful, and more addictive than the last.
Nearly 90 percent of cocaine users had first smoked tobacco, drank alcohol or used Marijuana. Research conducted by Columbia University’s National Center on Addiction & Substance Abuse as reported by Drug Watch International.