The newest federal drug survey counted 21.4 million Americans using marijuana daily or almost daily, more people than smoke cigarettes every day. The number that should worry public health officials is not the 21.4 million itself. It is what the peer-reviewed literature says awaits a population of that size using that way.
The 2025 National Survey on Drug Use and Health, released Monday by SAMHSA, shows daily or near-daily use up 21 percent since 2021. Nearly half of everyone who currently uses marijuana now uses it daily or almost daily. The studies on what frequent use does to the human body were not written with a population this large in mind.
Start with the heart. A 2024 study in the Journal of the American Heart Association, drawing on 434,000 adults, found daily marijuana users face a 25 percent higher risk of heart attack and a 42 percent higher risk of stroke than non-users, with risk climbing steadily with frequency of use. When that study published, its daily-use category described roughly 18 million Americans. It now describes 21.4 million.
The mental health findings are starker. The landmark EU-GEI study in The Lancet Psychiatry found daily users of high-potency marijuana five times more likely to develop a psychotic disorder than people who never use. High potency is no longer the exception; concentrates approaching 99 percent THC line dispensary shelves in every legal state. And a 2025 review in the Canadian Medical Association Journal reported that for people who visit an emergency room with marijuana-induced psychosis, subsequent schizophrenia risk runs 241.6 times baseline.
The longest shadow may be the most familiar one. A 2026 retrospective cohort study in Lung Cancer, matching nearly 150,000 patients per group across 20 years of medical records, linked cannabis use disorder to nearly four times the lung cancer risk of comparable non-users. Earlier work tied frequent use to three to five times the risk of head and neck cancers and eight times the risk of laryngeal cancer. America has run this experiment before, with cigarettes, and spent half a century counting the bodies.
The acute harms are not waiting for the long term. Federal DAWN data recorded 1.09 million marijuana-related emergency department visits in 2024, more than opioids. An estimated 2.8 million Americans a year now suffer cannabinoid hyperemesis syndrome, the severe cyclic vomiting condition tied to heavy use. And the addiction is keeping pace with the exposure: 19.3 million Americans now meet clinical criteria for marijuana use disorder, roughly one in three past-year users, second only to alcohol.
None of the daily-use figures appear in SAMHSA’s 157-page report. They sit in the appendix tables, where the survey’s own significance testing marks the growth since 2021 as statistically significant across every major measure of heavy use and addiction.
Epidemiology is arithmetic: risk multiplied by exposed population. The studies fixed the risk years ago. This week’s survey just updated the population, and it is 21.4 million people and rising.
That arithmetic lands first in the exam room. The cardiovascular findings appeared in the American Heart Association’s own journal; the lung cancer data will be familiar territory for oncologists; the psychosis numbers are already walking into emergency departments a million times a year. A patient population of 21.4 million daily users is large enough that most practitioners now see them routinely, whether they ask about marijuana or not. The research suggests the asking, and what follows from it, is due to become routine too.