In the study “Brain Function Outcomes of Recent and Lifetime Cannabis Use,” researchers found that “heavy lifetime cannabis use was associated with lower brain activation during a working memory task.” The findings suggested that regular use of marijuana is related to “short- and long-term brain function outcomes, especially during working memory tasks.” It’s the latest study to find a link between marijuana and memory function and abilities in the brain.  

“Working memory is the ability to retain information for a short period of time and use it,” Joshua Gowin, the lead author of the research, told CNN. 

“When you’re in the middle of a conversation with your boss, you need to remember what they said long enough to respond to it,” Gowin said. “Losing working memory means that retaining that information might require more effort and be more challenging.”

The study revealed that “ 63% of heavy lifetime cannabis users exhibited reduced brain activity during a working memory task, while 68% of recent users also demonstrated a similar impact.” The results come from using brain imaging technology to analyze the effects of marijuana use on 1,000 participants between 22 and 36 years old. The decreased brain activity correlated to poor assessments of the participants’ abilities to “retain and use information to perform tasks.”

Results from the study showed that those who used marijuana had a notable effect “on brain function during working memory tasks, meaning the observed impact is very unlikely to be due to random chance.” Additionally, these observations in the study were “unlikely to be due to random chance,” Neuroscience News reported. The study also found that significant marijuana use correlated with decreased “activity in the dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, and anterior insula regions of the brain.”

“We applied the highest standards to our research, setting rigorous thresholds for statistical significance across all seven cognitive function tests,” Gowin said. “To minimize the risk of false positives, we employed false discovery rate (FDR) correction. While some of the other tasks indicated potential cognitive impairment, only the working memory task showed a statistically significant impact.”

“In this study of young adults, lifetime history of heavy cannabis use was associated with lower brain activation during a working memory task,” read the conclusion of the study. “These findings identify negative outcomes associated with heavy lifetime cannabis use and working memory in healthy young adults that may be long lasting.”