The good news for public health is that there have been significant decreases in past-month cigarette smoking by young adults and recreational use of opioid medications in the past year compared to 10 years ago. The same goes with alcohol, which is still the most used substance but has seen declines in past-year, past-month, and daily drinking.

The bad news is that they are being replaced by marijuana and hallucinogens, and those increased significantly in 2021 compared to five and 10 years ago, reaching historic highs in this age group since 1988, according to the Monitoring the Future (MTF) panel study. Past-month marijuana vaping, which had significantly decreased in 2020, rebounded to pre-pandemic levels in 2021.

Since 1975, the Monitoring the Future study has annually surveyed substance use behaviors and attitudes among a nationally representative sample of teens. A longitudinal panel study component of MTF conducts follow-up surveys on a subset of these participants to track their drug use through adulthood. Participants self-report their drug use behaviors across three primary time periods – lifetime, past year (12 months), and past month (30 days). The MTF study is conducted by scientists at the University of Michigan’s Institute for Social Research, Ann Arbor, and is funded by NIDA, part of the National Institutes of Health.

Data for the 2021 survey were collected online from April 2021 through October 2021. Key findings in the young adult group include:

Marijuana Use: Past-year, past-month, and daily marijuana use (use on 20 or more occasions in the past 30 days) reached the highest levels ever recorded since these trends were first monitored in 1988. The proportion of young adults who reported past-year marijuana use reached 43% in 2021, a significant increase from 34% five years ago (2016) and 29% 10 years ago (2011). Marijuana use in the past month was reported by 29% of young adults in 2021, compared to 21% in 2016 and 17% in 2011. Daily marijuana use also significantly increased during these time periods, reported by 11% of young adults in 2021, compared to 8% in 2016 and 6% in 2011.

Hallucinogen Use: Past-year hallucinogen use had been relatively stable over the past few decades until 2020, when reports of use started to increase dramatically. In 2021, 8% of young adults reported past-year hallucinogen use, representing an all-time high since the category was first surveyed in 1988. By comparison, in 2016, 5% of young adults reported past-year hallucinogen use, and in 2011, only 3% reported use. Types of hallucinogens reported by participants included LSD, MDMA, mescaline, peyote, “shrooms” or psilocybin, and PCP. The only hallucinogen measured that significantly decreased in use was MDMA (also called ecstasy or Molly), showing statistically significant decreases within one year as well as the past five years – from 5% in both 2016 and 2020 to 3% in 2021.

Vaping: Nicotine vaping in the past month increased significantly among young adults in 2021 despite leveling off in 2020 during the earlier part of the pandemic. The continued increase in 2021 reflects a general long-term upward trend: in 2021, nicotine vaping prevalence nearly tripled to 16% compared to 6% in 2017, when the behavior was first recorded.

“As the drug landscape shifts over time, this data provides a window into the substances and patterns of use favored by young adults. We need to know more about how young adults are using drugs like marijuana and hallucinogens, and the health effects that result from consuming different potencies and forms of these substances,” said National Institute on Drug Abuse Director Nora Volkow, M.D. “Young adults are in a critical life stage and honing their ability to make informed choices. Understanding how substance use can impact the formative choices in young adulthood is critical to help position the new generations for success.”