fb-pixel Skip to main content

One month without marijuana could mean a better memory for young marijuana users

A marijuana enthusiast smokes a marijuana cigarette in April in the Boston Common.Matthew J. Lee/Globe Staff/Globe Staff

For young marijuana users looking to improve their memory, the answer could be just one month away, according to a new study by Massachusetts General Hospital.

One month without using marijuana, that is.

The new study, published in the Journal of Clinical Psychiatry, found that adolescents and young adults who regularly use marijuana — described as using marijuana at least once a week — could improve their cognitive functions by not using the substance for 30 days.

Researchers evaluated 88 participants in the study, all ages 16 to 25, and during cognitive testing, they found improvements, “specifically the ability to learn and recall new information,” only in the group of people who abstained.


And most of those improvements occurred within the first week of not using marijuana.

There were no noticeable changes in the group that continued using marijuana.

“Our findings provide two pieces of convincing evidence,” Randi Schuster, the lead author on the paper published about the study, said in a statement from MGH. “The first is that adolescents learn better when they are not using cannabis. The second — which is the good news part of the story — is that at least some of the deficits associated with cannabis use are not permanent and actually improve pretty quickly after cannabis use stops.”

Schuster, who is the director of neuropsychology at the Center for Addiction Medicine at MGH, said the study shows that young people who stop using marijuana could be more likely to succeed academically.

“We can confidently say that these findings strongly suggest that abstaining from cannabis helps young people learn, while continuing cannabis use may interfere with the learning process,” Schuster said.

According to the researchers, more than 13 percent of middle and high school students have reported using marijuana, and daily usage increases from eighth to 12th grade.


Felicia Gans can be reached at felicia.gans@globe.com. Follow her on Twitter @FeliciaGans.