Summary: A review of over 1, 000 young adults uncovered that both new and extensive career cannabis use lowers brain activity in areas essential for working memory, including the cerebral cortex and the front insula. This decreased activity is related to less memory-building, such as solving problems or following directions.
While different mental areas showed little effect, the findings emphasize the potential risks of cannabis on decision-making, memory, and interest. Researchers stress the need for more thorough research to compare the effects of cannabis on brain function across various ages and use patterns.
Important Information:
- Working Memory Impact: 68 % of recent users and 63 % of heavy users both reported decreased brain activity while using memory.
- Important Brain Regions: Cerebral cortex and the front insula, which are affected, had lower activity.
- Contraception Advice: Avoiding cannabis before mental things may improve memory performance.
Origin: University of Colorado
A new analyze, JAMA Network Open, published today explores the effects of both new and life cannabis use on brain function during mental tasks.
The review, the largest of its kind ever to be completed, examined the effects of cannabis use on over 1, 000 young people aged 22 to 36 using head imaging systems.
The researchers found that 68 % of recent users also had a similar impact, while 63 % of heavy-lifelong cannabis users reported a lower brain activity during a working memory task.
Working storage, the capacity to keep and use information to perform tasks, was linked to a lower performance on this drop in brain activity.
For instance, working storage allows a person to follow directions they’ve really been given or to mentally visualize and control information, like solving a math problem.
Studying cannabis ‘ effects on people’s health has grown more significant as the world’s use of it grows.
” By doing so, we may give a well-rounded knowing of both the benefits and risks of cannabis use, empowering people to make informed decisions and totally understand the possible consequences,” said the study’s second author Joshua Gowin, PhD, associate professor of radiology at the , University of Colorado School of Medicine , on the , University of Colorado Anschutz Medical Campus.
In the study, heavy users are considered young adults who’ve used cannabis more than 1000 times over their lifetime. Whereas, using 10 to 999 times was considered a moderate user and less than 10 times was considered a nonuser.
The researchers gave participants seven cognitive tasks to complete while studying the neural response of them during a magnetic resonance imaging ( MRI ) session.
The tasks tested working memory, reward, emotion, language, motor skills – such as tapping a finger to map brain control, relational assessment and theory of mind.
The researchers discovered that cannabis had a statistically significant impact on brain function while performing working memory tasks, making it very unlikely that the observed impact was caused by chance.
Both recent cannabis users and those who have used it for a long time saw this effect. The impact on the other tasks was less significant.
We set strict thresholds for statistical significance for all seven cognitive function tests in order to apply the highest standards to our research. 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, according to Gowin, had a statistically significant impact.
The researchers found that smoking a lot of marijuana appeared to lower brain activity in some of the brain’s dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, and anterior insula during working memory tasks.
These regions of the brain are involved in important cognitive functions such as decision-making, memory, attention and emotional processing.
Gowin mentions that their research also suggests that refraining from using cannabis before performing a cognitive task may help improve performance.
People should be aware of their relationship with marijuana because abstaining abruptly could also have an impact on their mental state. For example, heavy users may need to be more cautious,” Gowin says.
He continues,” There are many questions that still need to be answered regarding the effects of cannabis on the brain. Next, extensive, long-term studies are required to understand whether cannabis use directly alters brain function, how long these effects last, and how it affects various age groups.
About this news about memory and CUD
Author: Julia Milzer
Source: University of Colorado
Contact: Julia Milzer – University of Colorado
Image: The image is credited to Neuroscience News
Original Research: Open access.
Joshua Gowin and colleagues ‘” Brain Function Results of Recent and Long-Term Cannabis Use” JAMA Network Open
Abstract
Brain Function Results of Recent and Long-Term Cannabis Use
Importance
The need to better understand cannabis use’s recent and long-term brain activation outcomes has grown worldwide, but its effects on brain function are still undetermined.
Objective
To examine whether a large sample of young adults in the US’s population’s brain activation is related to lifetime histories of heavy cannabis use and recent cannabis use.
Design, Setting, and Participants ,  ,
This cross-sectional study used data ( 2017 release ) from the Human Connectome Project ( collected between August 2012 and 2015 ). Young adults ( aged 22-36 years ) with magnetic resonance imaging ( MRI), urine toxicology, and cannabis use data were included in the analysis. Data were analyzed from January 31 to July 30, 2024.
Exposures
The Semi-Structured Assessment for the Genetics of Alcoholism used to assess the history of heavy cannabis use and the prevalence of diagnosis of cannabis dependence.
People were classified as heavy lifetime cannabis users if they used it for more than 1000 times, as moderate users if they used it for 10 to 999 times, and as nonusers if they used less than 10 times.
On the day of the scanning, participants gave urine samples to check for recent usage. Diagnosis of cannabis dependence ( per , Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition , criteria ) was also included.
Main Outcomes and Measures ,  ,
Brain activation was assessed during each of the 7 tasks administered during the functional MRI session ( working memory, reward, emotion, language, motor, relational assessment, and theory of mind ). For each task, the mean activation was used, using regions that are connected to the primary contrast.
A linear mixed-effects regression model ( one model per task ) that looked at the relationship between lifetime cannabis use and recent cannabis use and the mean brain activation value was used as the primary analysis.
Results
The sample comprised 1003 adults ( mean]SD] age, 28.7]3.7] years, 470 men]46.9 % ] and 533 women]53.1 % ] ). A total of 63 participants were Asian ( 6.3 % ), 137 were Black ( 13.7 % ), and 762 were White ( 76.0 % ). For lifetime history criteria, 88 participants ( 8.8 % ) were classified as heavy cannabis users, 179 ( 17.8 % ) as moderate users, and 736 ( 73.4 % ) as nonusers.
Heavy lifetime use ( Cohen , d = −0.28]95 % CI, −0.50 to −0.06], false discovery rate corrected , P = .02 ) was associated with lower activation on the working memory task. The anterior insula, the medial prefrontal cortex, and the dorsolateral prefrontal cortex were some regions that were linked to a history of extensive use.
Recent cannabis use was linked to lower brain activity and performance in working memory and motor tasks, but the correlations between recent use and brain activation did not survive false discovery rate correction. No other tasks were linked to a lifetime history of frequent use, recent use, or diagnosis of dependence.
Conclusions and Relevance ,  ,
In this study of young adults, a lifetime of habituating to a high level of cannabis use was linked to less brain activation in a working memory task. These findings reveal negative effects that may be long-lasting and are related to long-term, long-term, and heavy cannabis use in healthy young adults.
