This is interesting but the causal relationship inferred by the article isn't supported by the evidence.
Unlike alcohol for example, there's no clear dose of THC where it can be concluded beyond a reasonable doubt that the person is impaired. A dose that might give a regular user a gentle buzz could render a first-time user completely stoned.
It's possible that these people were all incredibly stoned while driving but it's also possible that many drivers in Ohio are regular THC users and have such a high tolerance that their function is unimpaired.
And like always, there's the definite possibility of confounding factors, like reckless drivers also enjoying recreational drug use.
It's also important to note that the article's focus on legal limits is somewhat pointless. As there's no clear threshold above which one is impaired, the legal limits are somewhat arbitrary and are determined by other factors, like whether THC can be reliably tested at the given concentration.
Ultimately, as far as I can tell, the current state of things is that we're fairly certain that THC is able to impair driving ability but we have no idea how much THC is needed to do it or how impaired drivers become.
> A dose that might give a regular user a gentle buzz could render a first-time user completely stoned.
> It's possible that these people were all incredibly stoned while driving but it's also possible that many drivers in Ohio are regular THC users and have such a high tolerance that their function is unimpaired.
Can't you make this same argument with alcohol?
> Ultimately, as far as I can tell, the current state of things is that we're fairly certain that THC is able to impair driving ability but we have no idea how much THC is needed to do it or how impaired drivers become.
So how exactly would you propose states move forward with allowing people to consume THC and operate vehicles (or not)? We apparently can't even tell if someone is impaired in a reliable way.
Increased tolerance to THC actually makes it get you less high (for lack of a better term). You need a higher dose to be the same level of impaired. Real stoners can be totally functional and barely even high while hitting a vape every few minutes, but a first-time cannabis user might be on the floor after a single hit.
AFAIK the same isn’t true of alcohol - people who drink a lot may learn to be more functional while drunk, but I don’t believe that someone with a high tolerance has any faster of a reaction time than someone with a low tolerance, if their BACs are the same.
Technically the same thing applies, but to a much, much lesser degree.
While it's true that alcoholics can perform most tasks better than the average person after a few drinks, and there is some data showing they are less likely to get in accidents after drinking, they still become significantly impaired at about the same rate as everyone else.
They might have an advantage of a few drinks compared to a regular person, but they often close that gap.
The amount of non-impaired alcoholics driving around with BACs above the legal limit is negligible.
The human body's ability to adapt to THC is far greater than its ability to adapt to alcohol.
The Endocannabinoid system safely saturates, you can only have so much before the next dose doesn't really do much more.
Alcohol, on the other hand, continues to have about the same marginal effect, until toxicity is reached.
> While it's true that alcoholics can perform most tasks better than the average person after a few drinks, and there is some data showing they are less likely to get in accidents after drinking, they still become significantly impaired at about the same rate as everyone else.
This is completely self contradictory. It’s absolutely not “the same rate” if alcoholics can drink multiple additional drinks without showing impairment compared to nonalcoholics.
> They might have an advantage of a few drinks compared to a regular person, but they often close that gap.
This is kind of absurd. “Yeah, they can drink way more without impairment, but they’ll probably still drink to impairment.” This is borderline future crime.
I certainly don’t think we should allow alcoholics to drive with a higher BAC, mostly because the entire point of BAC is to make assessment more objective, but your logic is pretty tortured here.
I'm speaking in comparison to THC.
We are talking about order of magnitude differences with THC, especially in the blood after smoking or vaporizing.
The difference between a little drunk and very drunk is only a factor of 2, probably less.
I don't even think it's possible for a human to be 4 times as drunk as another also drunk human and survive.
The best way to think about tolerance to alcohol is buying a small constant headstart, while THC is better modeled as a difference of rates depending on tolerance.
I think most people will find that model useful, and the numbers (BAC) support that as a rule of thumb calculation.
Somehow you disagree that my model is accurate enough, but also agree that a constant cutoff is a good heuristic for legal intoxication from alcohol.
I have no idea about THC tolerance in comparison with alcohol. The numbers I see some people claim to consume is in your order of magnitude range vs what beginners are advised to use so it’s believable.
> Somehow you disagree that my model is accurate enough, but also agree that a constant cutoff is a good heuristic for legal intoxication from alcohol.
It’s not that I think your model isn’t accurate enough. It’s that I think your model is not consistent. A few extra drinks is enough to go from just barely under .08 to .16. If an alcoholic can run nearly double the alcohol intake (and double the BAC) of a nonalcoholic I don’t agree that this is nearly the same.
I agree with the constant cutoff because a constant reasonable limit is easier to administer. Less subjectivity for law enforcement is a good thing. I would probably support for the same for THC. “But I consume so much that I have a really high tolerance!” Ok, that’s not everyone else’s problem to deal with. Don’t drink if you’re over the limit.
They cant run double, it becomes clearer as the baseline goes up. At .16, the alcoholic would be up at .32 and at serious risk of dying from respiratory suppression. They’re more used to being drunk, but that doesn’t avoid the physical reality of alcohol toxicity.
It’s very different than THC where a 10x tolerance is pretty normal for a new user vs a heavy user. Relative to alcohol, that would be .08 vs .80 which is like twice the lethal limit.
Thus it’s very hard to set limits because one persons residual use from 6 hours ago is enough to get another person stoned off their ass. I don’t really have solutions there though.
I was using your “a few drinks more”. 4 standard beers over 2 hours supposedly puts a guy around .08. 3 more puts him at .16. But yeah, the near double drinking can’t continue because the alcoholic will just die at some point.
The THC thing is tough and I will leave it to experts and (more likely) politicians to hash it out. I’m not sure I want more reliance on field sobriety tests though. “His eyes were glassy and he was slurring. No, the camera can’t really capture the glassy eyes and don’t really pick up the slurring…”
> I don't even think it's possible for a human to be 4 times as drunk as another also drunk human and survive.
Considering some of the scores I have seen from the local police I beg to disagree. They have caught people with so much alcohol in their blood that your average person would probably be in a comma.
And I think your position on THC is irrational and probably motivated by your emotions.
I have smoked quite a bit and been around quite a lot of stoners, and they all think this way (oh, I'm used to it, no effect) but my experience tells me otherwise.
It's the power of magical thinking, but even a regular user is quite impaired, right after the first joint. I personally have been able to test this, with a quite lower performance in video games, even though I felt I was doing quite good. Stats said otherwise. And I can assure you that I was quite a heavy user at that time, since my brother was growing the stuff and I was getting it for free basically.
In my experience most cannabis users are quite irrational around the stuff because they want it to be magically better than what it is. But in the end, it is no better than alcohol and, in some ways, much worse: the effects last longer, pushing into the next day, which is what I believe happens in those accidents. The users believe they are more in control than they really are and their reaction times are quite worse, which would be actually very easy to measure...
> They might have an advantage of a few drinks compared to a regular person, but they often close that gap.
When the legal limit is 0.08 or lower, that's the difference between "too drunk for a non-alcoholic to drive" and "perfectly fine for an alcoholic", isn't it? Yet no court would accept that as an argument.
No because a once-daily user of THC will continue to test positive for 14+ days after quitting completely. For alcohol it's 6-12 hours. They are not comparable.
No, I was referring to the argument about tolerance.
"Your honor, my client is a raging alcoholic. Yes he blew 0.2, and while that may make the average person highly intoxicated, my client can function perfectly well at that level."
It is very hard to determine for thc-based intoxication via a test to determine not only when the person was intoxicated, but to what degree. They could have been stoned a week ago, or two weeks ago.
Other commentators are pointing out and linking to sources that explain how the tolerance bio-mechanisms are very different between alcohol and marijuana. It's an apples-to-oranges comparison that happen to use the same word "tolerance."
> So how exactly would you propose states move forward with allowing people to consume THC and operate vehicles
And that is the conundrum, ain't it? At the very least, the HN crowd is saying "don't take an approach that works well for A but not for B, and apply it to B anyways because it's an easy thing that makes your re-election campaign look like you're doing something instead of having the difficult, nuanced discussion of what IS the right enforcement model for something new."
The risk is these things tend to get cemented in once they're passed. We already did that once with marijuana when we scheduled it more dangerous than methamphetamine, fentanyl, and diazepam. But hey, that scheduling sure did win Nixon the political points he was looking for...
> Other commentators are pointing out and linking to sources that explain how the tolerance bio-mechanisms are very different between alcohol and marijuana. It's an apples-to-oranges comparison.
Yes I've seen that but I have a HARD time believing that two or three beers affects an alcoholic the same as it affects someone who drinks once a month. Alcohol tolerance is also a thing, why are people suggesting it isn't?
> The risk is these things tend to get cemented in once they're passed.
Yes but, it sounds like you have to have some sort of test for this, lest it turns into an "officer discretion" kind of thing since there's no reliable way to measure intoxication. Otherwise, it basically sounds like you can get as high as you want and no one can possibly charge you with DUI because of "you can't prove how long ago I took it" or "I have a tolerance, it doesn't affect me" (which totally does not fly as an argument in court with alcohol).
Alcohol tolerance doesn't meaningfully affect reaction time. We use the same word ("tolerance") for alcohol and marijuana, but the mechanisms are quite different.
Are you suggesting that two people, same weight, same metabolism, but one is a lifelong alcoholic and the other a once-per-month drinker — if they both have three or four drinks, the alcoholic would be just as impaired as the other person? I doubt that. The whole “functioning” part of “functioning alcoholic” implies that the alcoholic is able to, well, function in a manner a normal person wouldn’t if they had been drinking as heavily.
> The whole “functioning” part of “functioning alcoholic” implies that the alcoholic is able to, well, function in a manner a normal person wouldn’t if they had been drinking as heavily.
Well, It's like "functioning" in "high-functioning autism"; it's speaks to how well they can function in society, not how well they can operate a motor vehicle (nor anything to do with reaction times).
If they had the same BAC, yes. It may not make intuitive sense, but that’s just how alcohol tolerance works. The slow reaction times don’t go away. Alcohol in the bloodstream has a direct effect on your brain’s neural pathways that you can’t develop a resistance to.
Slower reaction times might not go away, but is there evidence you can't get better at handling slower reaction times? Practice generally improves performance in most tasks, I would presume someone with no experience at increased reaction times for instance would perform worse than someone experienced in it.
THC can remain in your system and be detected for 30 days. You are effectively proposing that it should be illegal to drive if you have ever used a THC product in the past month
The degree to which any given dose of THC affects an individual varies so wildly as to be completely useless as a baseline. To guarantee that 100% of debilitated users are detected, the threshold would have to be so low as to also detect a heavy user who smoked a joint two days ago.
Your argument is built on the supposition that there's a hard lower boundary on debilitating dosage. There is no such magic number, or it is nearly indistinguishable from zero.
It's sort of shocking. Compared to alcohol, where someone might plausibly get as drunk off of 1 drink as someone else might from 5, with THC the plausible ratio is more like 1:50 between naive and heavy users (IME).
>"Phosphatidylethanol (PEth) is a direct marker, formed only in the presence of ethanol, and can detect heavy or binge drinking for up to 4 weeks after consumption."
We should simultaneously use this marker to prove drunk driving instead of the clearly outdated direct measurements.
If we’re going to be this cruel it only makes sense to apply the same penalty to using a smartphone while driving, since it results in the same level of reaction time impairment as DWI.
>So until we have more research, we legislate to the case of the "first-time user completely stoned," no?
Throwing everyone under the bus because of the lowest common denominator is a shitty thing to do when we're talking $10k+ life altering fines here, but your attitude is how everything else involving driving is done so you'll probably get your way even if it's not moral or right.
INB4 people call me a stoner, haven't smoked weed in decades.
You say it's "not moral or right"; so, what would you suggest? I agree applying the lowest common denominator is not necessarily the best (nor fair) way to do it; but, how do you handle it?
Do we agree that there is some level that effects everyone, even if that level is different? Do we require all THC users -- smoking, edibles, vaping, topicals, etc -- be tested to determine the level where they become impaired?
No. What ought to be done is impairment testing, which is the direct way of checking if a driver is safe to drive regardless of the source of impairment.
The police cars should have a driving simulator installed that works with the steering wheel and the pedals of the car. Have suspects do on the spot a driving test in the sim. Pass/fail should be deterministic (the game would determine it).
This is a good point. Because we know that the THC level in somebody’s blood is so bad an indicator that it’s completely useless, we should use that measure to put the maximum number of people in jail with it for the maximum amount of time.
Thirty years ago, at a fair demonstration, they tried to determine passerby’s who were high. They did a quick reaction test, looked at eyes, and a short intoxication test using a driving video with questions.
They could not determine if people were high or tired but both were ineligible to drive according to their tests.
Never heard of any improvements or applications.
Can you point out where it ‘infers’ a causal relationship? The article as posted only makes the point that the percentage of dead people with THC in their system has remained static despite legalization.
> Unlike alcohol for example, there's no clear dose of THC where it can be concluded beyond a reasonable doubt that the person is impaired.
Anecdotally I do think that it's more the case with THC than alcohol, but even with alcohol it's actually not so cut and dry. Two anecdotes from my life:
Me personally - when I learned to drive I was a very heavy drinker. Not "need to drink daily", but I certainly had weeks where I ended every day quite drunk. So when I started driving I bought an expensive personal breathalyser, that the company verifies calibration of before shipping and once per year after that, because while I wasn't looking to get behind the wheel right after drinking I was aware that I often drank enough to still be under the influence the next morning.
I learned that strangely, despite my having a very high tolerance for alcohol back then (like, able to drink a bottle of spirits or a few bottles of wine and still present socially as not impolitely drunk, just enjoyably buzzed), I would feel too drunk to drive before my breathalyser readings showed me above the UK limits. I verified with some disposable tests set at the (even lower) French limits, and I could pass them too while feeling too drunk to be safe driving, after ~5-8 units (a few pints of beer, or half to a whole bottle of wine). If I drank more than that then I would start blowing over the limit, but drinking that amount I would reliably be under the legal limit despite drinking enough that most people would show as way over the limit. I've no idea why, maybe my body is just weird, maybe it's related to how high a tolerance I had (though, like I said, I would be feeling too drunk to feel safe driving even if legal), or what...
Second anecdote is about the husband of a colleague I once had, back before I was a driver myself. I was at their house, we had been drinking together for a few hours, but wanted to get across town for... that's another story. So I said I'll call a taxi, but he claimed to be able to drive safely despite having had 6 or 7 large beers. I assumed it was drunken bravado and insisted no, but then his wife started backing him up and I had a lot of trust in her judgement. As it happens, a week earlier I had been at a televised esports event where all the players had been given a reaction times test using a custom built piece of software, and I had that on my laptop. So I sat him down with it, and fuck me if his reaction times while drunk weren't better than 90% of the professional gamers who'd taken the test. I still felt like I was probably making a stupid decision agreeing to get in the car with him after that, but honestly the journey was about the smoothest drive I've ever witnessed. I'm fairly sure he would have blown way over the limit if tested (unless he was weird like me, back when I knew him was before I learned about my breathalyser results), but if police had seen him drive, or talked to him, they would never have guessed he might be drunk except for the smell of beer on his breath. And it definitely wasn't just me being too drunk to realise he was driving dangerously, a couple more times in the future I got into his car sober while he has been drinking, and felt equally safe each time.
I've no idea what % of people are like me, and can be technically legal on the tests despite feeling too drunk to be safe, or like that man who could be way over the limit yet still drive safer than most sober drivers. But there's at least some people like that! Ultimately the legal limits (which let's not forget, vary from country to country) are a best effort to be a rule of thumb, they're not a perfect indicator of where the safe line is.
Edit to add: I'm sure there are far more people who drunkenly believe they can drive safely despite what they've drunk and are wrong, than there are people like that man who genuinely can drive safely having drunk a fair bit. It's very common for alcohol to give people false confidence, so please don't use my anecdote to justify drunkenly deciding to drive.
Yes, many of us have also taken a college statistical course and understand correlation != causation. Yes, pop-sci articles will more heavily infer there is a causation, and this is bad for public trust in science. Also, dismissing all correlation studies is bad for public trust in science. There's several very good reasons why we do correlation studies, and they actual return interesting data.
I'd like to point out that blood alcohol levels are not 1 to 1 connected to level of impairment, but still serve as a useful indicator for ability to drive. Those with high tolerances behave differently than those with lower tolerances. The current Cannabis test is far from perfect, but seems to be the best proxy we have available for empirical evidence of level of impairment.
There's no methods of field sobriety testing that are actually reliable, what it's best at doing is allowing police to get probable cause even if a sober driver just happens to not be good at something they've not done before and are being asked to do in the dark and cold outside their car in a high stress moment; or, worse, if the police officer judging them is just biased and wanting to subjectively decide they failed.
I'm pretty sure lawyers' advice is generally to say no when asked to take a field sobriety test, as you're basically only asked to do it if the police already think you're going to fail and therefore will be at minimum subconsciously biases towards expecting that. Much better to only let them do any breath/blood tests they can legally insist on. (At least, if you are indeed sober. I don't know what the best advice is if you're going to fail those tests, maybe in that case a tiny chance of being convincing with a field sobriety test is worth the chance?)
Unlike alcohol for example, there's no clear dose of THC where it can be concluded beyond a reasonable doubt that the person is impaired. A dose that might give a regular user a gentle buzz could render a first-time user completely stoned.
It's possible that these people were all incredibly stoned while driving but it's also possible that many drivers in Ohio are regular THC users and have such a high tolerance that their function is unimpaired.
And like always, there's the definite possibility of confounding factors, like reckless drivers also enjoying recreational drug use.
It's also important to note that the article's focus on legal limits is somewhat pointless. As there's no clear threshold above which one is impaired, the legal limits are somewhat arbitrary and are determined by other factors, like whether THC can be reliably tested at the given concentration.
Ultimately, as far as I can tell, the current state of things is that we're fairly certain that THC is able to impair driving ability but we have no idea how much THC is needed to do it or how impaired drivers become.
For a somewhat reputable source, the NHTSA did a report to Congress in 2017: https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/812440...