While the strides in cannabis reform and accessibility have slowly distanced the plant from classic stoner stereotypes, with the spaciness and slow drawl of early potheads often portrayed in media from day’s past, a new study published last week in the journal Addiction points back to previous research, recognizing that getting high can affect cognitive function and could last well beyond that initial high, especially for adolescents.
CNN reported the results, along with a statement from study coauthor Dr. Alexandre Dumais, also an associate clinical professor of psychiatry at the University of Montreal, “Our study enabled us to highlight several areas of cognition impaired by cannabis use, including problems concentrating and difficulties remembering and learning, which may have considerable impact on users’ daily lives.”
He expanded, saying that cannabis use in youth could lead to reduced educational attachment and, in adults, poor work performance and dangerous driving. “These consequences may be worse in regular and heavy users,” Dumais said.
Dr. Megan Moreno, a professor of pediatrics at the University of Wisconsin School of Medicine and Public Health, said the impact of cannabis on the brain can be particularly detrimental for youth, who still have developing brains. Moreno was not involved in the study.
“This study provides strong evidence for negative cognitive effects of cannabis use, and should be taken as critical evidence to prioritize prevention of cannabis use in youth,” Moreno said. “And contrary to the time of Cheech and Chong, we now know that the brain continues to develop through age 25. Parents should be aware that adolescents using cannabis are at risk for damage to their most important organ, their brain.
The study reviewed previous studies on more than 43,000 people and found a negative impact of THC on the brain’s higher level of thinking, impacting executive functions like the ability to make decisions; remember important data; plan, organize and solve problems, along with controlling emotions and behavior.
Dumais indicated that scientists are still unsure about the ability for people to recover or reverse those effects on their brains. He cites research that has revealed THC is a fat-soluble compound that may be stored in body fat, so it is gradually released into the bloodstream for months. He added that high-quality research is needed to establish the long-term impact of cannabis exposure.
Some studies also suggest the negative effects of cannabis on the brain may ease after use is discontinued, but it likely depends on the amount, frequency and years of cannabis use, along with the age in which a person first began using cannabis.
“Thus far, the most consistent alterations produced by cannabis use, mostly its chronic use, during youth have been observed in the prefrontal cortex,” Dumais said. “Such alterations may potentially lead to a long-term disruption of cognitive and executive functions.”
Dumais added that some studies have shown early and frequent cannabis use among adolescents predicts poor cognition in adults. Pointing to his above statement, science does still need to continue sorting this piece out, but in the meantime, Dumais said preventative and interventional measures to educate youth on cannabis use and discourage young people from chronically using cannabis should be considered, since they are particularly susceptible to the effects of cannabis.
However, recent research also suggests, in contrast to beliefs that reform leads to increased cannabis use among young people, that there has been “no measurable difference” in the percentage of those in grades 9-12 reporting consumption of cannabis at least once in the past 30 days.
A U.S. Department of Education’s National Center for Education Statistics (NCES) analysis using data from the Youth Risk Behavior Surveillance System, which also found there were no statistically significant changes in the percentage of youth who say they’ve been offered, sold or gifted illegal drugs on school grounds over the last 30 days.
The data is from 2009-2019; there were no recreational markets in 2009, and that year, 21 percent of high school students reported use in the past 30 days. The first legal sales launched in Colorado in 2014, and five years later, 22 percent of teens reported they had recently used cannabis. The highest percentage of reported past 30-day was in 2011, before any states had legalized adult use.
