Doctors examined the effects of cannabis on brain function using MRI scans from thousands of individuals.

A team of medical professionals from the United States and Canada conducted the largest study to date using magnetic resonance imaging (MRI) to investigate the effects of cannabis on human brain functions. The study involved over a thousand young men and women, including both heavy marijuana smokers, some of whom were dependent, as well as more moderate users and those who had consumed cannabis fewer than ten times in their lives.

2025-01-30 10:02:00https://naked-science.ru/article/medicine/kannabis-rabota-mozga-mrt

The scientific study, the article of which was recently published in the journal JAMA Network Open, is based on data from the Human Connectome Project. As part of this project, volunteers recruited from Washington University in St. Louis (USA) among healthy individuals aged 22 to 37 underwent MRI scans. During the procedure, participants completed a series of tasks that activated different brain functions, including working memory, thinking, emotions, language and motor skills, among others.

Additionally, various information was collected through participant surveys, including socio-demographic data, information about cannabis use or other psychoactive substances, and any related dependencies. Before the MRI, urine samples were also taken from volunteers to assess the level of cannabis metabolites, which indicated the recency and intensity of use.

In the new study, researchers examined data from 1003 participants in the project. On average, they were 28.7 years old, with 470 men and 533 women. The group of heavy cannabis users consisted of 88 individuals, while 179 were classified as moderate users, and 736 were placed in the "non-users" category based on minimal experience (fewer than 10 times in their lifetime).

By comparing the MRI results with other information, researchers employed statistical analysis methods to establish that heavy cannabis users and those who had recently used cannabis exhibited reduced brain activity during working memory tasks compared to participants in the "non-users" group. No statistically significant correlation was found with other types of tasks.

It is important to note that working memory is essential for reasoning, cognitive tasks, solving logical problems, understanding complex information, and making decisions. It allows individuals to follow given instructions, mentally visualize information, manipulate it, and solve mathematical problems.

Given the increasing prevalence of cannabis use and the trend toward its full legalization in the USA and other countries, such research is becoming increasingly important as it expands knowledge about the risks associated with marijuana smoking, emphasized medical professionals. They also highlighted the need for further investigation into the effects of cannabis on the brain, as much remains unclear.

Authors of another scientific study previously found that heavy cannabis users were more likely to suffer from anxiety disorders. In a different article, researchers concluded from systematic meta-analysis that marijuana smoking could lead to persistent cognitive impairments. There is also known irreversible damage to the brains of offspring when cannabis is used during pregnancy.