Die größte US-Studie, an der 11.036 Kinder im Alter von 9 bis 10 bis 16 und 17 Jahren teilnahmen, ergab, dass Cannabiskonsum die kognitive Entwicklung verlangsamt, das Gedächtnis beeinträchtigt und die Lerngeschwindigkeit in entscheidenden Jahren des Gehirnwachstums verringert

>The researchers followed 11,036 children starting at ages 9 to 10 through ages 16 and 17, tracking both their cognitive performance and substance use. To get a clearer picture of cannabis use, the team combined self-reports with biological testing — such as hair, urine and saliva samples — which can detect recent to several months of drug exposure.
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>Across a range of skills — including memory, attention, language and processing speed — teens who used cannabis showed restricted growth over time compared to those who did not. In some cases, these teens performed just as well as — or even slightly better than — others when they were younger. But as they got older and started using cannabis, their progress leveled off, while their peers continued to improve.
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>The study also looked more closely at different components of cannabis. In a smaller group of participants, teens with evidence of tetrahydrocannabinol (THC) exposure — the main intoxicating ingredient in cannabis — showed worse memory over time than those who did not use cannabis. Teens with evidence of cannabidiol (CBD) did not show the same pattern, although that group was small.
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>“These results point to THC as a likely driver of the changes we’re seeing,” Wade said. “It also highlights how complicated cannabis products can be, especially since some products labeled as CBD may still contain THC.”
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>While the differences seen in the study were relatively modest, researchers say they could still matter. During adolescence, the brain is rapidly developing, and even small changes in memory, attention or thinking speed can affect school performance and daily life.
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>The researchers note that the study does not prove cannabis use directly causes these changes. Other factors — such as environment or personality — may play a role. However, the team accounted for many of these influences, including family background, mental health and use of other substances, as well as for each participant’s prior cognitive performance.

[Longitudinal neurocognitive trajectories in a large cohort of youth who use cannabis: combining self-report and toxicology | Neuropsychopharmacology](https://www.nature.com/articles/s41386-026-02395-1)

I would ask what is so fundamentally dysfunctional in an 11 year old’s life they feel the need to escape?

Nice to have proper research into this, but everybody who has been stoned for some time and has stopped using could tell them that this was the case. I’m over 50 and know people who have been smoking a lot for at least 3 decades, and it’s amazing how once smart, bright and joyful kids have turned into the biggest dumbfucks you can imagine. Glad I stopped before my brain would leak out.

It feels like the scientific consensus about what cannabis does to you is changing pretty rapidly. Or at least, that it’s reaching mainstream now.

Wish that it wasn’t pushed to be legalised so heavily just a few years prior.

Is this new info? It seems I’ve been seeing this stuff for decades. When I started smoking weed at 14, I was told I’d stunt my mental growth. I was fine with that. I figured 14 was a good age to be stuck. I’ve never stopped except for a couple of my 4 years in the military. Long successful career, successful marriage, 2 great kids. Retired comfortable. I guess it could have been a lot better?

Sounds like those kids may have had bad parents and do not realize their self worth. Anything amcan be harmful to you if you are not using it in the right way.

Let’s compare with the amount of trash food we joyfully give to our youth.

Many studies in the past have proven this already and its very important to keep this well known and talked about with how misunderstood cannabis is. Kids are at extreme risk for causing brain changes and delays that will cascade into their lives in ways they wont even know that its happening and how. I am lumping individuals with not fully developed prefrontal (cannabis has shown to significantly impair both acute short term and chronic use longterm) in this group which counts *most* adults younger than 25.

This is talking about delta 9 cannabis which is heavily regulated and understood, all of the uncontrolled thc analogs within uncontrolled vapes kids have access to are a whole other compounding factor in this danger.

The insidious effects of cannabis use at a young age get hidden due to the fact that they are indeed insidious effects and are easy to be completely downplayed as opposed to hard narcotics with more obvious downstream effects. Cannabis can be very good, but it can also be very harmful and addictive for both kids and adults.

Marijuana is not a „safe drug“ and never was. 

It’s not „safe“ for children or adults and it’s sale should be strictly regulated.

At those ages everything you do/put into your body is going to effect development, because you’re still developing.

I really don’t understand why they keep funding research that seeks to investigate what we already know and situations that we already know we’d seek to prevent occuring. No one out there is saying give cannabis to 11 years olds are they? Such a waste of time.

Uh no doi? Why its not for kids. Are we really that hard up for topics for studies? New study shows when you get struck by lightning you get electrocuted.

I’m sure this won’t be filled with tons of comments saying this isn’t true from the people who keep saying it’s not harmful at all since they smoked weed and turned out fine.