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[flagged] Association between cannabis use and subjective cognitive decline (eurekaselect.com)
41 points by delichon 6 months ago | hide | past | favorite | 57 comments



Subjective cognitive decline is a 'subjective' because it is perceived by the individual themselves. This means one of:

1) Weed dramatically reduces cognitive impairment.

2) Weed dramatically reduces an individual's ability to accurately asses their cognitive ability.

3) People who use weed are, for some other reason, dramatically less likely to suffer from cognitive impairment, or dramatically less able to accurately evaluate their own cognitive state.

4) The study itself is biased or flawed somehow.


Marijuana tends to affect people in one of two ways: they either get subdued or they get infatuated. Many people appear to get calmed and relaxed, they could just go to sleep, with pot affects them. Those that marijuana infatuate tend towards creative, intellectual, and creative intellectual pursuits. I am one such infatuated pot smoker, which I keep pretty much secret, because due to my pot smoking infatuations I've gradually made my way into uber secure work environments simply because I'm competent and fascinated by the work; while my counterparts are constantly burning out. It's a job to them. To me, it's fascinating play.


This sounds like classic indica verse sativa descriptions; the former being "couch lock" while the latter is "mental input seeking."

As a daily smoker (for over two decades), I definitely seek BOTH states of mind.

Regardless, glad to see you've remained fascinated with your career.


Kinda, with couch lock I can work (nothing too analytical tho), whereas sativa is so intense and panic inducing that I can’t even focus on a movie.

Afaik CBD counteracts the mind infatuation but leaves the body high on.


From my personal experience, having several friends that have been smoking since high school up to now (mid 30s), it's definitely 2).


But maybe having friends who smoke weed dramatically reduces your ability to assess your friends' assessment of their own cognitive ability.


Indeed, touché


The study is really broken from the beginning:

ask someone who take drugs to assess their own capacities, instead of measuring those from an objective perspective.

Obviously, "yes cannabis affects your ability to self-report your cognitive abilities";

it's a psychoactive drug that is mainly used for its cognitive effects, it's the main use/"advantage" of it ! (more rarely for pain management)

It's like if you ask alkaloidal cocaine (crack) users how they feel about their abilities.

They may report amazing bodily control enhancement, and seen from the outside it may be very different.

Even alcohol users, at the exit of night clubs, you sometimes see them report self-report increased abilities and decide to drive.

In that case, asking them to self-report doesn't give you much info on their actual abilities.


It's pretty well established that using cannabis while the brain is still developing has a negative impact on brain development. Additionally, from what I've observed among a few dozen people I've known over the years, people who start smoking in high school and continue without any substantial breaks through to adulthood tend to have a less healthy relationship with cannabis. They have a stronger tendency to fall into the pattern of using all day every day, and tend use much larger amounts than people who started using as adults or have taken substantial breaks (year +) from cannabis consumption as adults.


Another explanation is that weed smokers are less likely to self-report cognitive impairment, as that suggests it’s self-inflicted, which would cause feelings of regret and shame in many I suppose.


Yes, cognitive dissonance. This is my hunch.


I go with 4 for basically any study until it is verified independently. One big reason I tend to avoid science "news"


Is there a journal or news site that exclusively publishes on studies that have been replicated?


There should be a whole library of such studies, perhaps even with more than one successful replication.

All signal, no noise. Entire disciplines would be absent from it


Imagine if academic success were measured by having studies in such a library. Not just the original, but also the replications! Somehow we'd also need to incentivize publications of non-successful replications just as much though.


I wonder what an action plan to make this happen would look like.

It would appear that many researchers are aware the system is suboptimal but are resigned to it, or even benefit from it.

Maybe we should pitch a tech billionaire to fund a journal like this.


96% seems a bit high to not be mildly suspicious.


I have a sort of alternative explanation to your four.

One thing I've noticed with pot smokers is that many seem to be almost in love with the drug. I have had people try to explain to me the manifold benefits of hemp fibers or CBD or how cannabis kills cancers. I think this could quite plausibly extend to survey answers, where saying they suffer from cognitive decline would be a kind of admission of defeat and go against their core beliefs of cannabis as purely positive godly thing.

So basically some kind of psycho-cultural defense mechanism?


It's really a culture. People smoke cannabis to feel part of a clan or a cult, and then get hooked to the psychoactive effects.

It's always a game of social influence at the beginning, and sometimes later on.

Eventually, you may be pushed to smoke if you want to feel part of a social group and culture, and then, once inside, you have to follow the codes of it.

A large part of the cannabis cult(ure) is to preach the substance to everybody around you, to get it depenalized, legalized, and want everybody to have good views on it so they can take it more in public, and be socially more accepted, not considered like a junkie.

The end-game of it, is to do everything to get more of it, consciously or not.

Then, from that perspective, now you have someone that asks you: "is cannabis good for you ?" (just in other words).

Your goal to consume cheaper and higher quality of the substance, without legal risks, and to have approval of your friends, then what do you say ?

Of course "yes it's great".

There is also a survivorship bias in the study: once you feel that your cognitive abilities decline, you typically stop smoking cannabis.

The extreme case: people with dementia are automatically excluded because they cannot even smoke or purchase the product.


Strong likelihood of 4.

“The reason for cannabis use, but not frequency and method, is associated with SCD.”

The finding is clearly an artifact of the methodology. BRFSS is probably not the right way to study this.


It’s likely 1.

Most adults are busy reducing brain cell count thru use of alcohol and other poisons. Marijuana on the other hand is proven to increase brain cell count thru neurogenesis in the hippocampus [1].

This is not possible for adults without marijuana [2].

[1] https://pubmed.ncbi.nlm.nih.gov/16224541/

[2] https://www.ncbi.nlm.nih.gov/search/research-news/1588/


Your [2] is outdated information. 2018 my not seem like that long ago, but science doesn't stop.

EX: https://academic.oup.com/sleep/article/44/2/zsaa173/5986548

However, growing evidence suggests that new cells are not only “born” constitutively in the adult hypothalamus, but many of these cells also differentiate into neurons and glia and serve specific functions.


Checking the paper, alcohol is a covariate.


A few thoughts after having read only the abstract:

1. The decline (which is reported to be less frequent in cannabis users) is self-reported subjective cognitive decline based on users’ experience.

2. I think that one of the hallmarks of cannabis use is an immediate decline in short-term memory. I believe this usually reverses itself after some time (hours or days).

3. I have used a lot of cannabis in the past. I stopped entirely - for now - for quite some time and I think my mental acuity is currently at its peak over my lifetime and may be growing.

4. Not only is cannabis a very highly cultivated plant whose potency has been increasing a lot for decades (citation needed), there are a ton of cannabis-derived products out there today that have just a ton of THC, way more than one could get by smoking even the highest potency bud. I think this has prohably changed the game entirely. I used a few of them and I would absolutely recommend caution, far beyond the legitimate caution I would recommend for even smoking cannabis bud.


Yes, much has changed since the time of Dave.

https://www.youtube.com/watch?v=ACfNSqsi_mE

Probably your last point is key. Even a little dab will do ya nowadays or you'll forget what I was talking about. Wait.


I see your Dave and send you love from Sister Mary Elephant...

https://www.youtube.com/watch?v=Ftds_ae072M


Great clip…


That's odd considering cannabis use was shown to decrease REM sleep and thus memory processing and consolidation.


CBD on the other hand in "mid range" doses decreases REM sleep latency and (any dose?) also decreases REM sleep suppression related to anxiety. This is something that I imagine needs more study, as there is a huge variability in THC to CBD ratios in legally available cannabis.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116407

Although most recreational cannabis is high THC : low CBD, there is ever-growing demand for more balanced strains. There's no telling what the average looks like in black and grey markets (although high THC is certainly the default assumption given its intoxicating effects). Before we make blanket statements about the impact of cannabis on sleep, we should probably seek to answer questions like, what is the overall impact on REM sleep with cannabis that has a 4:1 ratio of THC to CBD or lower?


First: REM sleep etc. is not a proven cause-effect relation. Second: THC or some other compound might negatively affect that. Third: cognitive decline is broader than memory. Fourth: it was self-reported impression of cognitive decline.

I don't think there's reason to expect any relation between REM sleep and the outcome to hold.


Yeah, that's a real annoyance if you're using cannabis to help manage pain.


Just to be clear, 96% decreased odds of cognitive decline = good? Rather confusing way to put it


No, of subjective cognitive decline. Not decline as measured through testing, decline as self-reported.

Basically pot makes you less self-aware.


Basically pot makes you less self-aware.

Which is exactly the effect some people are seeking with it.


That is not what is being said.


My personal experience and in some cases a negative one. Cannabis makes me hyper self aware to the point of over analyzing myself.


> Basically pot makes you less self-aware.

That is one interpretation, yes. But not the only possible one.

Is it good? Maybe. Maybe not good but neutral. Maybe actually bad. More research is needed.


Thanks. I was having such a hard time parsing this that I was beginning to have my own experience of subjective cognitive decline. Glad to know I'm not alone.

So those that get stoned are more confident in their mind's ability than those that don't?


confusing maybe if you haven't smoked a bowl yet this morning...


Cognitive decline is scary, because if it happens gradually enough, you wouldn’t even realize it’s happening.

Was I sharper a few years ago? Maybe, I really couldn’t tell you, and it’s not like I’ve been taking cognitive evaluations to check.

Scary thoughts.


From reading the abstract.

> Compared to non-users, non-medical cannabis use was significantly associated with 96% decreased odds of SCD (aOR=0.04, 95% CI=0.01-0.44, p<.01). Medical (aOR=0.46, 95% CI=0.06-3.61, p=.46) and dual medical and non-medical use (aOR=0.30, 95% CI=0.03-2.92, p=.30) were also associated with decreased odds of SCD, although not significant.

I'm not a native speaker but if non-medical use of cannabis has a different outcome than medical and mixed use than it seems plausible that there are other - more important - factors at play or do I misunderstand the paragraph?


Subjective Cognitive Decline (SCD) is the self-reported experience of worsening or more frequent confusion or memory loss.

Lower odds is seemingly a good thing (if you’re somebody that enjoys retaining memory)


The issue with this is if you have memory loss, you may also have memory loss about the memory loss, so lower numbers here may actually not reflect a real increase in memory retention.


> The reason for cannabis use, but not frequency and method, is associated with SCD. Further research is needed to investigate the mechanisms that may contribute to the observed associations between non-medical cannabis use and decreased odds of SCD.


What is SCD?


Subjective Cognitive Decline (SCD) refers to an individual's self-perceived experience of worsening or more frequent confusion and memory loss, not necessarily confirmed by clinical diagnostics.


Subjective cannabis delinquency


If continuous use removes all possibility for being bored, or displaces your hobbies instead of enhancing them, then cognitive progress is stagnated, imo.


"self reported... thats how we ended up with the mental state of our two current presidential candidates


I wonder if it's related to the fact stoners are likely to go to bed on time.


I think that depends on the usage and what they're smoking tbf. Weed can play havok with sleep or be an aid.


I can agree with this claim, however i think it's subjective to individuals


That's why the call it subjective decline.


How does subjective decline correlate with objective decline, amongst stoners?


Weed just makes you care less about completing the cognitive exercises of the exam.


Associated with implies no causality, but of course everybody knows that, right?


"Stoners deny cannabis bad"




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