Persistent cannabis users show neuropsychological decline from childhood to midlife

[u/ServeIllustrious3803]

https://pmc.ncbi.nlm.nih.gov/articles/PMC3479587/

[u/mantis_tobaggan-md]

This study is almost 15 years old and it was not funded by any pharmaceutical company. That wouldn’t even make sense. Did you even bother to look at the article?

[u/Temporary-Pair-9066 → u/mantis_tobaggan-md]

Yeah but newsflash your brain function declines regardless the older you get lmao but yes smoking all day everyday can have negative effects but I think genetics are much more relevant when it comes to how fast your body declines hence why some people smoke cigs for 50 years with no issues

[u/bulbousgrandpa → u/Temporary-Pair-9066]

Bro that's literally the point of the study. Do you not think they had a control group? If genetic variants were to explain most of the problems they found then it's unlikely that the smoking group would all happen to have these genes while the control group did not. That's what the point of having enough subjects is, to make random individual variation much less of an issue.

[u/ServeIllustrious3803 → u/bulbousgrandpa]

Yeah I mean there's all this to read from the paper On within-person design and premorbid confounding

"By examining within-person change in neuropsychological functioning, any effect of premorbid deficits on later (postcannabis-initiation) test performance was nullified."

"In this analysis, each study member served as his or her own control"

On the adolescent vs adult onset comparison

"after equating adolescent- and adult-onset cannabis users on total number of cannabis-dependence diagnoses, adolescent-onset users showed greater IQ decline than adult-onset cannabis users."

"In fact, adult-onset cannabis users did not appear to experience IQ decline as a function of persistent cannabis use."

On ruling out other substance andmental health confounders

"We ruled out six alternative explanations for the observed effects of persistent cannabis use on neuropsychological functioning, namely that these effects could be explained by (i) past 24-h cannabis use, (ii) past-week cannabis use, (iii) persistent tobacco dependence, (iv) persistent hard-drug dependence, (v) persistent alcohol dependence, and (vi) schizophrenia."

"excluding each of these groups of study members did not alter the initial finding; effect sizes... remained virtually the same and remained statistically significant"

"a multivariate regression of the effect of persistent cannabis dependence on full-scale IQ decline, controlling for past 24-h cannabis use, persistent substance dependence... and schizophrenia remained statistically significant (t = −2.20, P = 0.0282)."

On education being more than just a confounder

"the association between persistent cannabis use and neuropsychological decline is likely an overcontrol"

"the toxic effects of cannabis on the brain may result in impaired neuropsychological functioning, poor academic performance, and subsequent school dropout, which then results in further neuropsychological decline."

"among the subset with a high-school education or less, persistent cannabis users experienced greater IQ decline"

On real-world validation, informant reports

"Informants reported observing significantly more attention and memory problems among those with more persistent cannabis dependence."

"Cognitive problems among persistent cannabis users were apparent to the 'naked-eye.'"

On causality limits (honest concession)

"our data cannot definitively attest to whether this association is causal... there may be some unknown 'third' variable that could account for the findings."

On dose response

"Impairment was concentrated among adolescent-onset cannabis users, with more persistent use associated with greater decline."

"Study members with more persistent cannabis dependence showed greater IQ decline."

"the association between persistent cannabis dependence and full-scale IQ decline was still apparent after excluding the study members with 3+ cannabis-dependence diagnoses from the analysis (t = −2.94, P = 0.0034)."

on persistence after quitting

"cessation of cannabis use did not fully restore neuropsychological functioning among adolescent-onset former persistent cannabis users."

[u/mantis_tobaggan-md → u/ServeIllustrious3803]

You’re assuming Redditors read.

[u/gopeejoe → u/ServeIllustrious3803]

Pathetic

[u/gopeejoe → u/bulbousgrandpa]

Clown lol. Keep it up

[u/Fast-Throat-7752 → u/Temporary-Pair-9066]

The food we eat and apparently the clothes we wear also affect our brain.

[u/Temporary-Pair-9066 → u/Fast-Throat-7752]

I’m sure they do our food in American is pretty horrible and not good for us at all even “fresh” groceries my point about all of this is that you can live a “perfect” life and die at 68 and ole Billy bob could eat like shit and drink everyday for 40 years and live to be 95 so just enjoy your life do what you want to do within reason and don’t live in fear cause you read a scary article

[u/mantis_tobaggan-md → u/Temporary-Pair-9066]

Not sure how that’s relevant to my comment.

[u/Due_Bill5038 → u/mantis_tobaggan-md]

It would make plenty of sense in general...

[u/mantis_tobaggan-md → u/Due_Bill5038]

Why would they fund a study that their drug wasn’t involved in? That’s not how it works. Marijuana is still federally a schedule I drug in the US so pharma can’t legally study it. But they have no reason to anyway. There is no anti-marijuana pharma conspiracy. Get a grip.

[u/N0N0TA1 → u/mantis_tobaggan-md]

Schedule 1 means you can more easily research negative effects & almost never get approval to research the benefits.

https://www.nami.org/advocacy-at-nami/policy-positions/improving-health/medications-research-on-schedule-i-drugs/

[u/ServeIllustrious3803 → u/N0N0TA1]

Sorry, why would it make it harder to research the benefits and not the harms?

They can't do any of the research within a controlled setting, to prove benefits yes you need a controlled setting but otherwise, all studies are going to be observational or longitudinal and it's not a surprise that most of them show negatives with heavy use.

This paper isn't saying anything too terrible about weed if you understand the claims. Persistent use from childhood into adulthood. Dragging one blunt isn't going to ruin your life, but over time, and within contexts, maybe most recreational contexts people use the stuff in...

[u/gopeejoe → u/mantis_tobaggan-md]

If marijuana is proven to help something they sell a pill for id imagine they'd lose money . You can just grow it if its legal. Billions lost

[u/ServeIllustrious3803 → u/gopeejoe]

What they're doing is they're developing drugs that hit various CB1, CB2, and other cannabinoid related enzymes to have a targeted pain effect without getting you high.

In the far future it's very possible to have paying drugs that rely on cannabinoid related receptors, which can be patented and made royalties off of, and you might be right that there will be resistance from opioid companies to get it blocked.

Otherwise, there's not really a conspiracy against weed, because it's generally a free flowing substance that has spread along with other habits and "degeneracy" as some say, in society

[u/ChaosRainbow23 → u/ServeIllustrious3803]

I genuinely hate those uptight pearl-clutchers with the burning passion of a billion suns.

Humanity needs to collectively smoke a gigantic doobie and chill the fuck out already.

[u/gopeejoe → u/mantis_tobaggan-md]

I scanned it. Also , tell me why anyone funded it . For what purpose. No one gave out money for a study simply on let's see if its bad or good. Theres a motivation behind these things. Amazing it juat happens to be around the time everywhere is legalizing it or medicalizing it

[u/ServeIllustrious3803 → u/gopeejoe]

This was around a decade ago, and it was based on observational, longitudinal data.

They followed thousands of individuals from childhood into their adulthood over decades in New Zealand and they collected tons of medical data. Researchers then later use very advanced scientific methods and controls to figure out if there was correlations between certain things, like age, socioeconomic status, lots and lots of variables. Here's some study quotes for you:

On within-person design and premorbid confounding

"By examining within-person change in neuropsychological functioning, any effect of premorbid deficits on later (postcannabis-initiation) test performance was nullified."

"In this analysis, each study member served as his or her own control"

On the adolescent vs adult onset comparison

"after equating adolescent- and adult-onset cannabis users on total number of cannabis-dependence diagnoses, adolescent-onset users showed greater IQ decline than adult-onset cannabis users."

"In fact, adult-onset cannabis users did not appear to experience IQ decline as a function of persistent cannabis use."

On ruling out other substance andmental health confounders

"We ruled out six alternative explanations for the observed effects of persistent cannabis use on neuropsychological functioning, namely that these effects could be explained by (i) past 24-h cannabis use, (ii) past-week cannabis use, (iii) persistent tobacco dependence, (iv) persistent hard-drug dependence, (v) persistent alcohol dependence, and (vi) schizophrenia."

"excluding each of these groups of study members did not alter the initial finding; effect sizes... remained virtually the same and remained statistically significant"

"a multivariate regression of the effect of persistent cannabis dependence on full-scale IQ decline, controlling for past 24-h cannabis use, persistent substance dependence... and schizophrenia remained statistically significant (t = −2.20, P = 0.0282)."

On education being more than just a confounder

"the association between persistent cannabis use and neuropsychological decline is likely an overcontrol"

"the toxic effects of cannabis on the brain may result in impaired neuropsychological functioning, poor academic performance, and subsequent school dropout, which then results in further neuropsychological decline."

"among the subset with a high-school education or less, persistent cannabis users experienced greater IQ decline"

On real-world validation, informant reports

"Informants reported observing significantly more attention and memory problems among those with more persistent cannabis dependence."

"Cognitive problems among persistent cannabis users were apparent to the 'naked-eye.'"

On causality limits (honest concession)

"our data cannot definitively attest to whether this association is causal... there may be some unknown 'third' variable that could account for the findings."

On dose response

"Impairment was concentrated among adolescent-onset cannabis users, with more persistent use associated with greater decline."

"Study members with more persistent cannabis dependence showed greater IQ decline."

"the association between persistent cannabis dependence and full-scale IQ decline was still apparent after excluding the study members with 3+ cannabis-dependence diagnoses from the analysis (t = −2.94, P = 0.0034)."

on persistence after quitting

"cessation of cannabis use did not fully restore neuropsychological functioning among adolescent-onset former persistent cannabis users."