For decades, the classic picture of teen substance use was a familiar trio: alcohol, cigarettes, and marijuana. New data suggests that triad has quietly turned on its axis. Today the tightest bond runs between two substances, nicotine and cannabis, joined by vaping.
That is the picture emerging from a new analysis of the Adolescent Brain Cognitive Development study, the largest long-term study of youth brain development in the country, and it lines up closely with the government’s own national surveys.
Start with the headline number. By age 16, roughly 38 percent of kids have used alcohol, marijuana, or nicotine at least once. That nearly matches Monitoring the Future, which found 39 percent of 10th graders have tried at least one of the three, a rare and clean point of agreement between a research cohort and a national survey.
The more telling finding is what travels together. In the ABCD data, once a teen uses either nicotine or cannabis, the odds they use the other are higher than for any pairing involving alcohol. Alcohol remains the most widespread substance, but it is no longer the glue. Nicotine and cannabis are. By 16, nearly 8 in 10 kids who use both alcohol and nicotine also use cannabis.
Federal data points the same way. SAMHSA’s 2024 National Survey on Drug Use and Health found that among adolescents using more than one substance in the past month, the single most common combination was nicotine and marijuana, at 41.6 percent, not any alcohol pairing. The CDC’s Youth Risk Behavior Survey shows another shift: girls now match or outpace boys, with nearly 1 in 4 female high schoolers currently drinking and about 1 in 5 using marijuana.
The common thread is the device. Vaping has become the shared delivery system for both nicotine and THC, a discreet, high-potency, easy-to-hide pipeline the old cigarette-and-beer model never had. Federal tobacco data has tracked that migration for years, with e-cigarettes now dominating youth nicotine use.
One caveat belongs in any honest read of the numbers. The national surveys all show teen substance use at or near historic lows and trending down. The rising figures in the ABCD cohort reflect kids aging across the study, not a national spike. Even so, the finding lands: about 4 in 10 teens have used a substance by 16, and when they use more than one, weed and vapes increasingly arrive together.
The old triad is fading. The new one runs on a vape pen.