Roughly 1 in 5 Americans aged 12 or older used an illicit drug in the past year, with marijuana accounting for the vast majority of that use. The national numbers come from SAMHSA’s National Survey on Drug Use and Health, which surveys hundreds of thousands of people annually across the civilian population. Beyond marijuana, millions more misuse prescription medications or use hallucinogens, stimulants, and opioids.
Marijuana Is the Most Widely Used Drug
Cannabis dominates the statistics. About 52.5 million Americans, or roughly 19% of the population, used it at least once in 2021. No other substance comes close in terms of how many people use it. As state-level legalization has expanded, cannabis use has steadily climbed over the past decade, and it now represents the bulk of what gets counted as “illicit drug use” in federal surveys.
Hallucinogen Use Is Rising Fast
Hallucinogens have seen one of the sharpest increases of any drug category in recent years. In 2024, 3.6% of people aged 12 or older (10.4 million people) used a hallucinogen in the past year, up from 2.7% just three years earlier. Psilocybin, the active compound in “magic mushrooms,” drove much of that growth, with 2.7% of the population reporting past-year use. MDMA (ecstasy) came in at 0.7%, and LSD at 0.6%.
Young adults aged 18 to 25 use hallucinogens at far higher rates than any other age group: 6.8%, or about 2.4 million people. Among adolescents aged 12 to 17, the rate was 1.6%.
Opioid Misuse
In 2024, 2.7% of Americans aged 12 or older, about 7.8 million people, misused opioids in the past year. That figure combines heroin use with misuse of prescription painkillers like oxycodone and hydrocodone. While prescription painkiller misuse makes up the larger share of that number, heroin and the rise of illicitly manufactured fentanyl have driven the overdose crisis that kills tens of thousands annually.
Prescription Drug Misuse
Prescription drugs are misused far more often than most people realize. In 2021, among people aged 12 or older:
- Pain relievers: 3.1% (8.7 million people) misused prescription opioid painkillers
- Tranquilizers and sedatives: 1.7% (4.9 million people) misused drugs like benzodiazepines or sleep aids
- Stimulants: 1.3% (3.7 million people) misused medications like those prescribed for ADHD
“Misuse” in these surveys means taking a medication in a way other than prescribed: higher doses, using someone else’s prescription, or taking it to get high rather than for a medical condition.
Inhalants
About 1.1% of the population aged 12 or older (3.2 million people) used inhalants in the past year as of 2024. This category covers substances like aerosol sprays, solvents, and nitrous oxide. Inhalant use skews younger than nearly every other drug: 3.7% of adolescents aged 12 to 17 reported past-year use, compared to 2.0% of young adults and just 0.7% of adults 26 and older. It’s one of the few substance categories where teenagers have higher usage rates than adults.
How Many Americans Have a Substance Use Disorder
Using a drug and having a problem with it are different things, and the survey tracks both. In 2023, 48.5 million people aged 12 or older, about 17.1% of the population, met the clinical criteria for a substance use disorder. That includes both alcohol and drugs. Breaking it down: 28.9 million had an alcohol use disorder, 27.2 million had a drug use disorder, and 7.5 million had both.
That 17.1% figure is striking because it means roughly 1 in 6 Americans is dealing with a level of substance use that causes significant problems in their daily life, whether that’s an inability to cut back, withdrawal symptoms, or interference with work and relationships.
Age Makes a Big Difference
Drug use is not evenly distributed across age groups. Young adults aged 18 to 25 consistently report the highest rates for nearly every substance. Hallucinogen use among young adults (6.8%) is more than four times the rate for adolescents (1.6%). The same pattern holds for marijuana and prescription drug misuse. Adults 26 and older generally have the lowest rates of use for most illegal drugs, though they make up the largest absolute number of users simply because there are so many more of them.
Adolescents aged 12 to 17 are the exception for inhalants, where their usage rate (3.7%) tops every other age group. This likely reflects the easy availability of household products and the fact that inhalants are often one of the first substances young teens encounter.
What the Numbers Include
The national survey covers the civilian, non-institutionalized population aged 12 and older. That means it excludes people in prisons, jails, long-term hospitals, and military barracks, groups that may have different usage patterns. It tracks tobacco, alcohol, marijuana, hallucinogens, inhalants, and the misuse of prescription medications, along with use of drugs like heroin, cocaine, and methamphetamine. The survey relies on self-reporting, so actual usage rates could be somewhat higher than what people are willing to disclose, even in an anonymous questionnaire.