Study: Pot impairs teens’ memory
But research shows damage ‘not permanent’
Teens and young adults who lay off marijuana for a month can expect to see improvements in memory function, according to a new study from Massachusetts General Hospital.
“Adolescents learn better when they are not using cannabis,” said Dr. Randi Schuster, director of neuropsychology at Mass. General’s Center for Addiction Medicine and lead author of the study.
Schuster said the good news is that “at least some of the deficits associated with cannabis use are not permanent and actually improve pretty quickly after cannabis use stops.”
The study, which was published in the Journal of Clinical Psychiatry, shows that one month of abstinence from cannabis resulted in memory improvement in teens and young adults who were regular cannabis users. The participants of the study, all from the Boston area, used cannabis ranging from once a week to once a day.
Schuster said this makes the study unique and shows that even using cannabis once a week could impact a young adult’s ability to learn.
The participants of the study, ages 16 to 25, completed regular assessments of their thinking and memory during the monthlong study period. Cognitive testing found that memory improved only among those who stopped using cannabis — and the improvements happened mostly during the first week of abstinence.
“For us, it really highlights the need for smart prevention programming for our young vulnerable users,” Schuster said.
The study notes that teen cannabis use is common, with more than 13 percent of middle and high school students reporting pot use and rates of daily use increasing between grades eight and 12.
Students reported easy accessibility to cannabis, and attitudes of harm perception in 2016 were at or near historic lows, with only one in three 12th-grade students perceiving great risk in regular use, according to the study.
Jim Borghesani, a marijuana industry consultant, argued that rates of cannabis use have not increased among adolescents.
“They point to perception of harm because they can't point to actual use rates,” Borghesani said, adding that he doesn’t see the study leading to any change in perceptions.
Borghesani said the study highlights the need for a legalized pot market.
“Anybody who is truly concerned about underage use should embrace a legal sales system because it contains safeguards against selling to underage consumers,” he said.
According to Schuster, there are still a lot of open questions that need to be answered, including whether attention may also improve and if memory will continue to improve during longer periods of discontinued marijuana use.
Another clinical trial will begin soon to answer these questions. It will follow young cannabis users for six months to investigate whether cognition improves beyond a 30-day time period.