This year saw the steepest decline in teenage drug abuse in decades, according to a recent survey by the National Institute on Drug Abuse (NIDA) that was published on Wednesday.

NIDA’s Monitoring the Future survey found that high school teenagers were reporting lower drug use throughout 2021. In terms of legal drugs, the researchers found that marijuana and alcohol use went down significantly in the last year among 10th and 12th graders.

Dr. Nora Volkow, the director of NIDA said that the agency had "never seen such dramatic decreases" in teenage drug use in such a short period of time. In fact, the survey recorded the lowest rate of teen drug abuse since it first began in 1975.

"These data are unprecedented and highlight one unexpected potential consequence of the COVID-19 pandemic, which caused seismic shifts in the day-to-day lives of adolescents,” said Volkow.

Underage alcohol abuse fell to 28.5% and 46.5% among 10th and 12th graders in 2021 from 40.7% and 55.3% respectively in 2020. For marijuana use, the rate drops were smaller but still beneath last year's levels. Vaping remained the most common way to use nicotine for teens, but this too dropped from 31% to 20% among 10th-graders, and from 35% to 27% among 12th-graders.

Illicit drug use saw similar declines as well. Among tenth graders who reported use of any illegal drug beyond marijuana, only 5.1% reported doing so compared to the 8.6% who did so in 2020. Twelfth graders recorded slightly higher rates at 7.2% this year, but this fell from 11.4% in 2020.

Why the rate of teenage drug abuse decreased in 2021 does not have a single explanation, but lead researcher Dr. Richard A. Miech echoed Dr. Volcow’s assessment that the COVID-19 pandemic played an important part. He expressed hope that these findings can contribute to a better understanding of drug use patterns among adolescents or if these impacts are long-lasting.

"We knew that this year’s data would illuminate how the COVID-19 pandemic may have impacted substance use among young people, and in the coming years, we will find out whether those impacts are long-lasting as we continue tracking the drug use patterns of these unique cohorts of adolescents," said Dr. Miech.

Teenagers’ substance abuse habits remain a central focus for researchers, who are concerned about how it will impact their health or development.

Vaping, the most popular method recorded in this survey, has come under particular scrutiny from researchers and regulators alike because of its negative side effects on teenagers. Marijuana use has also drawn more attention for its negative side effects on teens because of its increasing availability as more states legalize what was once an illegal substance.