December 24, 2025
Martijn Scheffer/UNSPLASH.COM
Using cannabis products just once a month was associated with worse grades and more emotional turmoil in teenagers, according to a study published Tuesday in the journal Pediatrics.
Any amount of regular marijuana use has a negative impact on teens' academic performance, new research suggests.
Using cannabis products just once a month was associated with worse grades and more emotional turmoil in teenagers, according to a study published Tuesday in the journal Pediatrics.
“A few ‘harmless’ joints can snowball into real academic consequences," said Dr. Ryan Sultan, the study's lead author. "Teens using it regularly often struggle to focus, miss school, and may lose interest in their future plans.”
The findings come at a time when overall drug use has been at historically low levels among teens. Marijuana is the exception — with about 1 in 5 high schoolers reporting using cannabis, according to the National Center for Drug Abuse Statistics.
At the same time, cannabis products have become much more potent in recent decades. Levels of THC, or Delta-9-tetrahydrocannabinol — which causes the mood-altering effects of the drug — rose from about 4% in 1995 to more than 16% in 2022. Most cannabis products available now have potencies over 20%, according to a recent report.
For the new study, researchers analyzed data from more than 160,000 eighth-, 10th- and 12th-graders from national surveys conducted between 2018 and 2022. More than a quarter of the group said they used cannabis products, with 18% reporting near-daily use, 14% weekly use and 18% monthly use.
Monthly users were twice as likely to do poorly in school and get into fights compared with students who did not use. Students who used cannabis products were also at higher risk for depression and anxiety.
Students who used weed nearly every day were four times more likely to have low grades and to be disengaged from school, the study found.
“A teenager’s brain is still developing the circuits for learning, self-control, and emotional regulation,” said Dr. Tim Becker, one of the study's co-authors and a child and adolescent psychiatrist at NewYork-Presbyterian Westchester Behavioral Health. “Using cannabis, even casually, during these critical growth periods interferes with those processes and can derail normal development.”
