I didn't review the study (wouldn't even know how to do that), but I did read the article and it doesn't say anything about permanent effects. In fact, the participants were aged 22-36, so definitely past high school age.
The title makes it sound like smoking weed causes permanent brain damage, but I don't think that's what they found at all
> The researchers found that both recent and heavy lifetime cannabis use was associated with a statistically significant reduction in brain activity only during the working memory task.
So they observed reduced memory function during a memory task for people who smoked recently or were "heavy" smokers, but not in any of the other tests. Maybe the heavy smokers have permanent brain damage, but the OP at least don't mention any findings like that.
"The researchers found that both recent and heavy lifetime cannabis use was associated with a statistically significant reduction in brain activity only during the working memory task."
They theorized that abstention may help long term users, but that wasn't in write-up
Also this is not necessarily a universally bad thing.
For example if I need to work through something from first principles as opposed to instant recall I may develop a more novel understanding.
Anecdotally I have found a number of individuals that are great a remembering and therefore excel in some academic situations are the quite intellectual rigid and unable to think beyond what they are told.
But as a disclaimer I'm not advocating marijuana use as it can have detrimental affects on motivation for example.
You are misunderstanding the meaning of working memory. Working memory is very short-term and small; it's what you use when you read the second half of an equation and still remember what the first half said.
A reduction in working memory is a direct reduction in cognitive capability for some/many tasks.
The title makes it sound like smoking weed causes permanent brain damage, but I don't think that's what they found at all
> The researchers found that both recent and heavy lifetime cannabis use was associated with a statistically significant reduction in brain activity only during the working memory task.
So they observed reduced memory function during a memory task for people who smoked recently or were "heavy" smokers, but not in any of the other tests. Maybe the heavy smokers have permanent brain damage, but the OP at least don't mention any findings like that.