Alcohol, Not Marijuana, Was the Most Common First Substance Among US 12th Graders | Research

The takeaway

In a nationally representative sample of US 12th graders, alcohol was the most commonly used first substance, and students who started drinking in 6th grade reported significantly more illicit drug use than those who started in 9th grade or later.

Parents, educators, and policymakers interested in understanding substance use progression among adolescents.

Alcohol, not marijuana, was the most common first substance in the path to polysubstance use

What the researchers found

Researchers examined data from 2,835 US 12th graders to determine which substance adolescents use first and how the age of first use relates to later drug involvement.

Alcohol was the most commonly used substance, and the majority of polysubstance users consumed alcohol before trying tobacco or marijuana. This challenges the popular "gateway drug" narrative that typically focuses on marijuana.

Students who started drinking in 6th grade reported significantly more lifetime illicit substance use and more frequent illicit substance use than those who began in 9th grade or later. The effect sizes for these differences were large (eta squared = 0.30 and 0.28).

Why it matters

The finding that alcohol, not marijuana, is the most common entry point to substance use has implications for prevention priorities. It suggests that school-based prevention programs targeting alcohol use, potentially starting as early as third grade, could have a greater impact on reducing later illicit drug use.

The numbers in context

2,835 12th graders sampled. Alcohol was the most common first substance. 6th-grade alcohol initiators: mean 1.9 illicit substances (SD 1.7) and mean frequency of 6.0 (SD 6.5). 9th-grade-or-later initiators had significantly lower use. Effect sizes: eta squared = 0.30 and 0.28 (large).

How the study worked

The study analyzed data from a nationally representative sample of 2,835 US 12th graders. Researchers examined the sequence of substance initiation (alcohol, tobacco, marijuana) and used statistical analysis to compare illicit drug use outcomes based on age of first alcohol use.

What this study cannot tell us

The cross-sectional design captures associations at one time point rather than following students over time. Self-reported substance use may be inaccurate. The study cannot determine whether early alcohol use causes later illicit drug use or whether both reflect common underlying risk factors.

How to read the evidence

This is a cross-sectional analysis of nationally representative data with large effect sizes. It provides moderate evidence on substance use sequence but cannot establish causation.

When this study was published

Published in 2016. Substance use patterns among adolescents may have shifted with changing cannabis legalization and vaping trends.

The bigger picture

The "gateway drug" concept has long been debated in drug policy. This study's finding that alcohol is the most common first substance in the progression toward polysubstance use challenges the framing that typically places marijuana in this role and has implications for how prevention resources are allocated.

Questions still open

Would targeted alcohol prevention in elementary school reduce later illicit drug use? Is the sequence of substance initiation changing as cannabis becomes more accessible?

Common questions

Is marijuana the gateway drug?

This study found that alcohol, not marijuana, was the most commonly used first substance, and most polysubstance users consumed alcohol before either tobacco or marijuana. The "gateway" concept is more complex than typically portrayed, with alcohol playing a more prominent role in the sequence.

Why does starting young matter so much?

Students who began drinking in 6th grade had substantially more illicit drug use than those who started in 9th grade. Early substance use may occur during a more vulnerable developmental period, or it may be a marker for other risk factors that also predict later drug use.

Read the original research

Prioritizing Alcohol Prevention: Establishing Alcohol as the Gateway Drug and Linking Age of First Drink With Illicit Drug Use.

The Journal of school health, 86(1), 31-8

View on PubMed ↗Publisher’s paper ↗

Citation

Barry, Adam E; King, Jessica; Sears, Cynthia; Harville, Cedric; Bondoc, Irina; Joseph, Kessy. (2016). Prioritizing Alcohol Prevention: Establishing Alcohol as the Gateway Drug and Linking Age of First Drink With Illicit Drug Use.. The Journal of school health, 86(1), 31-8. https://doi.org/10.1111/josh.12351