You probably picture alcohol when you imagine a teenager rushed to the ER on a Saturday night.
That picture has not vanished, but the numbers behind it have shifted more than most parents realize.
A new study in the American Journal of Psychiatry tracked US teens who ended up in the ER for a substance-related problem.
In 84 percent of those visits, cannabis was listed somewhere in the record. Alcohol appeared in only about one in three.
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Researchers at Washington University School of Medicine in St. Louis analyzed more than 1.3 million people aged 16 to 64.
Each had at least one substance-related emergency encounter between January 2016 and December 2023.
Only 19 percent of substance-related visits in adults aged 55 to 64 involved cannabis, while 70 percent involved alcohol. Among teens, those numbers were almost flipped.
The fastest shift
Cannabis-involved visits rose in every young age group. The sharpest climb came in people aged 19 to 24, with the share growing by about 1.8 percentage points a year. For teens aged 16 to 18, the annual rise was closer to 0.8 points.
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Alcohol is not going away either. The steepest single trend in the whole study involved adults aged 25 to 34. For them, alcohol as the primary reason for hospitalization rose 3.6 percentage points a year.
Kevin Y. Xu, an assistant professor of psychiatry at WashU Medicine, led the analysis.
He said in a statement from the university that cannabis use has been trending up and alcohol use trending down for years.
Until now, he added, there was little high-quality data on which patterns were actually sending people to the ER.
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Potency and other substances complicate the picture
The study counted any ER visit or hospitalization where cannabis appeared anywhere in the diagnosis list. The visit itself could have been for a car crash, a psychiatric crisis or an unrelated medical problem.
Nearly half of the cannabis-involved encounters also involved at least one other substance.
Even so, the researchers noted rising cannabis-linked hospital admissions involving psychosis and severe vomiting among younger people.
Heavy adolescent cannabis use has long been tied to higher risk of psychotic symptoms, though most young people who use cannabis never experience them.
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Earlier research has also found that teens who use cannabis face about twice the risk of two serious mental health disorders.
A CDC Morbidity and Mortality Weekly Report from August 2026 found a related signal.
ER visits for cannabis hyperemesis syndrome, a cycle of severe nausea, vomiting and belly pain tied to cannabis use, were highest in people aged 15 to 24.
Potency is part of the picture. Today's cannabis products can deliver far more THC, the active ingredient, than products from a decade ago. Concentrates can run well above half THC by weight.
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For a parent worried about a teen using cannabis, the direct step is a conversation with their doctor.
Repeated vomiting, severe anxiety or signs of a psychotic episode warrant prompt medical attention.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.