A recent study published in JAMA Network Open delves into the impact of both recent and lifetime cannabis use on brain function during cognitive tasks. This study, the largest of its kind to date, examined over 1,000 young adults aged 22 to 36 using brain imaging technology. The researchers discovered that heavy cannabis users, both recent and lifetime, exhibited reduced brain activity during a working memory task.
Working memory is crucial for tasks that require retaining and utilizing information to perform activities. It enables individuals to follow instructions, visualize and manipulate information, and solve problems. The decline in brain activity observed in heavy cannabis users was associated with poorer performance on working memory tasks.
Dr. Joshua Gowin, the study’s lead author and assistant professor of radiology at the University of Colorado School of Medicine, emphasized the importance of understanding the effects of cannabis on human health as its use continues to rise globally. By comprehensively studying the benefits and risks associated with cannabis use, individuals can make informed decisions regarding its consumption.
In the study, heavy users were classified as individuals who had used cannabis over 1,000 times in their lifetime, while moderate users had used it 10 to 999 times. Participants underwent magnetic resonance imaging (MRI) sessions and completed seven cognitive tasks testing various functions such as working memory, reward, emotion, language, motor skills, relational assessment, and theory of mind.
The researchers found that cannabis had a significant impact on brain function during working memory tasks, with reduced brain activity observed in specific regions associated with decision-making, memory, attention, and emotional processing. Although the impact was less pronounced in other cognitive tasks, the working memory task showed a statistically significant effect.
Dr. Gowin highlighted the potential benefits of abstaining from cannabis use before engaging in cognitive tasks to enhance performance. However, abrupt cessation of cannabis use could also disrupt cognition, particularly in heavy users. Further research is needed to explore the direct effects of cannabis on brain function, the duration of these effects, and their impact on different age groups.
The study, titled “Brain Function Outcomes of Recent and Lifetime Cannabis Use,” was published in JAMA Network Open in 2025. For more information, you can access the full article through the DOI: 10.1001/jamanetworkopen.2024.57069.
This research sheds light on the complex relationship between cannabis use and brain function, underscoring the need for continued investigation into the long-term effects of cannabis on cognitive performance. By gaining a deeper understanding of these dynamics, individuals can make informed choices regarding their cannabis consumption habits.
