Young adults are using marijuana and hallucinogenic drugs at unprecedented levels. In recent findings from Monitoring the Future, a long-term study of drug abuse supported by the National Institute on Drug Abuse since 1975, and published September 6 in JAMA Health Forum, the rate of adults ages 19 to 30 reporting marijuana use increased from 34% in 2016 to 43% in 2021. The use of hallucinogens also rose significantly, from 5% in 2016 to 8% in 2021. Alcohol remains the most popular substance used by young adults and, while the overall drinking rate has declined in the past 10 years, in 2021 high-intensity drinking (10+ consecutive drinks) rose to its highest level ever (13%) and binge drinking (5+ consecutive drinks) picked up to prepandemic levels (32%) after a decline during the 2020 pandemic year (28%).