More frequent marijuana use could damage an important memory capacity

A recent large-scale study has revealed new findings on the impact of cannabis use on memory. Published in the medical journal JAMA Network Open, this analysis is the largest to date and has evaluated more than 1,000 people between the ages of 22 and 36 to understand how this substance affects working memory.

Cannabis is one of the most widely used drugs in the world, both for recreational and medicinal purposes. As its legalization advances in various regions, interest in its effects on health, particularly on brain function, is also growing. Although its impact on the nervous system has been previously investigated, this study provides a more detailed view supported by neuroimaging that reveals alterations in brain activity associated with memory.

The research team used functional magnetic resonance imaging (fMRI) to analyze participants’ brain activity as they performed tasks involving working memory, a cognitive function essential for processing and temporarily storing information. The results indicated that both recent and regular users showed a significant reduction in activation of certain areas of the brain compared to non-cannabis users.

The most affected regions included the dorsolateral prefrontal cortex, the dorsomedial prefrontal cortex, and the anterior insula. These areas play a key role in decision-making, attention, emotional regulation, and of course, working memory. According to the researchers, the decrease in brain activity suggests that cannabis may interfere with the brain's ability to retain and manipulate information in real time.

Working memory is essential for many everyday tasks, such as remembering instructions, performing mathematical calculations, or following complex conversations. When this function is impaired, people may experience difficulty concentrating, making sound decisions, and processing information efficiently.

The study found that 63 percent of regular users and 68 percent of recent users showed reduced brain activation during these cognitive tests. This indicates that the effects of cannabis not only affect those who use it regularly, but also those who have used it in the period close to the assessment.

One of the key factors in this phenomenon is tetrahydrocannabinol (THC), the main psychoactive compound in cannabis. THC binds to cannabinoid receptors in the brain, particularly in areas involved in memory and cognition, which can disrupt neuronal communication and reduce the efficiency of brain processes.

One area that still requires further research is the permanence of these effects. Although some studies suggest that cognitive function may improve after a period of abstinence, it is not clear whether there is irreversible damage in those who have consumed cannabis for long periods.

Researchers stress the importance of consumers being aware of these potential effects, especially in contexts where working memory is crucial, such as academic or professional settings. Avoiding cannabis use before performing tasks that require a high level of concentration and information processing could help minimize the impact on cognitive performance.

The study also highlights the need to further explore the effects of cannabis on different age groups and people with different consumption frequencies. The current findings provide an important foundation, but questions remain about how it affects the long term and whether certain groups may be more vulnerable than others.