Vaporize Cannabis. Get behind the wheel of a car. Pull out onto the highway. This is not the beginning of an accident report. This is a study Dr. Tom Arkell and team ran on an actual highway in the Netherlands. Dr. Arkell is from Australia, his research is partially supported by the Lambert Iniative and the driving was done near Maastricht University. The study looked at CBD vs THC vs a combo of THC/CBD vs placebo. You definitely want to listen to this multinational study if just to hear what "placebo cannabis" is. Driving and cannabis and Kirk and Trevor! What more do you need?
E64 - Driving Under the Influence with Dr. Tom Arkell
Meet our guest
- Effect of Cannabidiol and Δ9-Tetrahydrocannabinol on Driving PerformanceA Randomized Clinical Trial
- Cannabis and Driving Webinar
- Lambert Initiative for Cannabinoid Therapeutics
Music ByKraftwerk Autobahn
(Yes we have a SOCAN membership to use these songs all legal and proper like)
- Cannabis-Impairment.pdf (127 Downloads)
Trevor: We're back.
Kirk: We're back.
Trevor: Time change from here to Australia. Time change from here to Australia is hard because people on Australia and people in Canada are only awake at the same time for a few hours a day. Why do I know this? I had an interview. Yeah, I had an interview. He was like plus 17 hours from us. So, I was interviewing tomorrow, which was cool. So, Dr. Tom Arkell with a bunch of other people. But we got to interview Dr. Tom Arkell about driving and cannabis. And Kirk, they put people, they gave them cannabis and put them on the highway and saw what happened.
Kirk: What? say that again. they, they... a double what...
Trevor: They gave them cannabis. they vaporized the cannabis
Kirk: Gave them Cannabis, yes?
Trevor: they used cannabis, they use vaporized cannabis. And then they went for a 50-kilometer drive out the 50-kilometer drive back. I can't believe they let them do that. That that that part still blows my mind.
Kirk: In Austraila.
Trevor: Well that's where it gets complicated. The researchers were in Australia, but the driving was done in the Netherlands. So, it was a multinational event.
Kirk: Holy crow. I have not listened to this yet so this is almost as close to a double-blind placebo study you can get.
Trevor: Yeah, it's people basically were their own control. So it's now it's only twenty six people and there's other little bits you could pick at it. But really, you know, before they had done trials in like basically computer simulators and those are all good. But this is not a close course, not a computer game. This is in a car on a highway with other people. I had a lot of fun with this one, this it's it's good and nerdy and lots of numbers, but just fascinating, fascinating that they let people do this. I enjoyed this interview a lot.
Trevor: So welcome back to Reefer Madness on the line. Today, we have Dr. Tom Arkell from Australia. Dr. Arkell, tell us a little bit about what your background is and how it relates to driving and cannabis.
Dr. Arkell: So I'm a psychopharmacologist. I got into this space about seven or eight years ago after my undergrad degree, and I became particularly interested in this idea of how drugs can affect the brain and behavior and our experience of the world around us. And that at first led me over to New York. I spent a bit of time at Columbia working just as a research assistant on a study looking at the effects of MDMA and THC on prosocial processing and prolog threat" and things like this. I came back to Sydney and was working across a couple of different clinical cannabis studies. And this is where the Lambert Initiative first came into it, which was I know you were planning to ask me about this later, but I'll
Trevor: No, No go, go, go.
Dr. Arkell: So, we received a 30, 34, 35 million dollars philanthropic donation from Barry and Joy Lambert over here. And that gave us a wonderful and very exciting opportunity to start looking at a whole lot of areas relating to medical cannabis. So, I took the driving thing and ran with it because there wasn't too many people doing research in this space and there wasn't really anything coming out around medical cannabis. And it seemed like this was a research area that that needed a little more digging into. So I first ran a study in Sydney, which was similar to this study we recently published, but looking at simulated driving performance. And this was quite new to me. The first two years, we're trying to get the study up and running. where it's an absolute nightmare. Australia was not a good place to be doing this kind of research at the time. People were horrified when we said we wanted to give people cannabis and see what happened to their driving. You know, we had to import cannabis from Canada at the time from Tilray.
Dr. Arkell: and things kept getting wrong. Import licenses would expire by the time was the batch was ready to be sent out and then a new batch reprocessed. But the TCH/CBD concentrations were a little bit different and it wasn't what was listed on state health permit. So we had to redo all of them. And it was just, it was such a mess. But eventually we got that up and running and then it went well. And then after that, that led me to the Netherlands to run this study, which we most recently completed with the Draw markers over there. And that's sort of where I am today. So, I suppose I've been involved in this clinical cannabis research for about seven years now. The driving thing was new to me and that was really I had an opportunity with my PhD to take on a new research area that I thought was interesting. And it's been very exciting.
Trevor: And that's fascinating in so many things. So Lambert Initiative, their benefactors really just donated a big wad of money and said, hey, you guys go look at how medicinal cannabis works.
Dr. Arkell: Yeah, I think there was a little more sort of structure to the money, but essentially that was the idea.
Trevor: That's a researchers dream.
Dr. Arkell: Exactly. It's incredible. And their grand-daughter has Dravet syndrome now. OK, a terrible form of childhood epilepsy. And she was she was having hundreds of seizures die. And her parents have been effectively treating her with a cannabis oil. But they were up against legal challenges here in Australia. And I think like a lot of other parents at a similar time here in Australia were going, you know, this is crazy. This is the only thing that's working for my child. But I'm basically being prosecuted for. And so that sort of sparked this. I think that was a real personal interest for them and something that really hit close to home. And the sorry lab at the University of Sydney that previously became the Lambert initiative was in a good position to start embarking on this sort of research.
Trevor: Thank you. OK, so let's talk about the actual study. So, the driving. I was telling people at work today about this interview and everyone had a giggle about. "So they gave them cannabis and did what?" So, where were so we had twenty-six people, relatively young, relatively healthy, and they were driving in physical cars. Now is this around a close track or was this where were they actually driving?
Dr. Arkell: So this is on a public highway in the Netherlands, very close to Maastricht University. This is in traffic in the middle of the day on a I think it's a two-lane highway it could three, I don't remember off the top of my head. But it's a highway. It's a public highway.
Trevor: That's what I thought I read. But I just I thought I'd better check that because that, again, sounded a little was great, that we have real world experience, but then sound a little crazy that we are allowed to do that. And I just got to say. So I'm older than you. I've got two, one daughter. She's almost nineteen. She's been drive for a while. I have a son who who's 15, if it wasn't for Covid right now, he would be in driver's-ed and I would be sitting in that passenger seat gritting my teeth, hoping he wasn't hitting anything and wishing I had like brakes and accelerators there. So, I really felt for these driving instructors that you had had in there. I can only imagine what they were going through with these drivers. So, I really felt for them. That was fascinating to me as well. But before I go too far down that one. The how you measured how well they drove this, that the standard deviation of lateral position. How about explaining that? I think that's key for everyone to understand what you were measuring.
Dr. Arkell: So, it's a slightly messy term, but essentially what a standard deviation of lateral position or STOP is measuring is how much a driver is moving around on the road. So, it's essentially a measure of lane weaving, but really it accounts for swerving and overcorrecting as well. So lateral position is just simply the distance between the car, the center of the car and the lane markings on either side of the car. So, in this case, it's that line markings on the left-hand side of the car. And then the standard deviation of that is just a measure of variance. So how much how much variability is there in a driver's movement in the road, like in their lane? And the reason why it's a particularly good measure of drug induced driving impairment is that it's a very hard thing to control for. So, you know, as a driver, it's fairly easy to control your speed. You can easily put a little more pressure on the brake pedal or less on the accelerator and slow down. There are a whole lot of things that you can control for pretty easily, but something like STOP is a very automatic process, is something that's very overlearned, something that you just do automatically because that's what you've learned to do while you're driving. So people find it very hard to compensate for deficits due to alcohol or drugs or sleep deprivation, whatever it may be.
Trevor: OK, now let's talk about your participants. I read twenty-six participants. They seemed to be relatively young, relatively healthy. But for the interests of this, what did you mean, their occasional cannabis users? What how did you define occasional cannabis user?
Dr. Arkell: So, these are people that have at least ten lifetime experiences with cannabis, but they're using no more than twice a week. So we had quite a range of responses. He has some people that hadn't used participants, rather some people that hadn't used for quite a while, and then some people that were using on weekends, you know, maybe on a Friday or Saturday night at a party. These are mostly university students that are participating in this. And the idea is that we're capturing people that have some experience with cannabis. They know how it's going to affect them. And partly as a safety thing, you know, just to be sure that the people are going to be going out and driving and are in a position to at least handle the effects of cannabis and that they used to these effects and they know what to expect, but not people that are using daily. People that are using daily tend to not follow instructions to not use cannabis for the duration of the study. And they also often have residual levels of THC on metabolites in their blood, which makes our piqué analysis really messy.
Trevor: And we'll come back to it probably at the end. But that specifically excludes medicinal users. But you talk about that, the analysis will come back at the end. So just again, so we have the set up properly. The cannabis was vaporized, it wasn't smoked and it wasn't ingested other than I assumed that was the probably the easiest to control for. Why did you pick vaporized?
Dr. Arkell: Vaporizing is better than smoking. It's more efficient delivery method. We lose less THC to side stream smoke. We have more control over the inhalation procedure because it's not burning and there's no combustion. There's no loss of a vapor in between inhalations. So, we had people vaporizer for about ten minutes we control. So, we told them to inhale for a certain number of seconds, hold their breath and then exhale. And then we just keep going basically until that vapors are no longer visible. So normally it takes a certain number of inhalations. We expect by ten minutes that will be all finished. But if there's still vapor coming out, then we'll keep going for a little bit longer. So, it's just a more efficient and easy to control method than smoking that reflects what most people are actually using in the community to administer cannabis.
Trevor: OK, and you also had them do some surveys on how we'll come back to the surveys. So, I first want to ask about you had them do some, it sounded more or less like video games to see how the cannabis was affecting them. Tell me a little bit about those computerized things that you were doing to test things like reaction time.
Dr. Arkell: OK, yes, we had a range of cognitive tasks. And this was this is a battery of three tasks that takes about ten minutes. And these are different tasks, measuring things like processing speed and how quickly people can take on information and perform an appropriate response. Divided attention, how well people attend to different stimuli and response time, reaction time in there as well. So, we're trying to capture a number of cognitive domains that we know, do tend to be affected by THC. So, people would come into our behavioral lab. We did this a couple of times in each session. And prior to this, people were trained on these. So, we got people baseline performance up to a certain level where they were no longer improving. And these were just simply three tasks. People responded using the computer mouse or the keyboard that the task took between sort of two and four minutes each. And we've used this previously and they come from a battery that's actually from Johns Hopkins in the U.S. We have a pretty good idea of how sensitive they are to cannabis effects. We know they work well, basically.
Trevor: OK, and you also ask them a bunch of questions about how they're feeling, everything from literally how stoned do you feel to how well do you think you're driving? Tell us a little bit about those survey questions and visual analog skills you gave them.
Dr. Arkell: So, these are simply just pen and paper questions. You know, people have a question. For example, how strong do you feel. On one end of the scale is going to say not stoned at all? And then the other end of the at the end of the scale, it's going to say very stoned. And these are 10-centimeter lines that people just put a mark in the middle of the line or whatever they feel is sort of best represents how they're feeling at that time. And these are common sorts of questions that we use to assess drug effects over time. So it gives us a really nice sort of measure of how people are changing their response to the drug over the course of the session. So I think we had six or seven measurements across the session.
Trevor: OK, so I know it sounds like I spent a lot of time doing the how I was set up, but I just thought all those were interesting. OK, so you're now you're getting ready to put people into cars. What are you giving them? What are they're? the patients or the participants are their own control. So how did the experiment actually run?
Dr. Arkell: That's exactly right. So, people came back for four separate sessions, each one week a part. It took over a month to run each participant and they come in for a medical assessment and then a training, a training day. And then the four test days. Everyone received placebo. They received THC dominant cannabis. There received a CBD dominant cannabis and THC:CBD equivalent cannabis. So a 1:1 strain. The order of those in which they were administered was randomized and counterbalanced. So we try and make sure that the same number of people receive, for example, placebo in the first session and THC in the second session and so forth. So once people had vaporized the cannabis, this is about 40 minutes into the session, the first driving test occurred. The driving instructor would come up and meet them, make sure they were feeling OK and OK to drive. You would take them down to the garage, take out the car, and they would go off driving for an hour or so. Like I mentioned before, this is happening in traffic on the highway that would drive 50 kilometers up the road. They would turn around and drive 50 kilometers back. So it's one hundred kilometers of driving and it took around an hour. And they did this twice in each session. So forty minutes and then again at four hours so we could get a sense of how long was this driving impairment actually lasting.
Trevor: Fascinating. Placebo for vaporizing cannabis. How do you, how do you do that. How do you make me think I'm vaporizing cannabis when I'm not really vaporize on cannabis.
Dr. Arkell: So, this is cannabis that had all of its THC removed from it and CBD and active cannabinoids. The cannabis still retains the original terpene profile of the active cannabis strain. So.
Trevor: So, it still smells good.
Dr. Arkell: Exactly. So, it still smells. It's still tastes the same. It's not perfect. This is an issue with, you know, Human Cannabis Administration studies, that's something that I think is widely recognized and that we're working on. It's not perfect, but it's pretty good. So, it smells and tastes like the original cannabis. There's some vapor as well. So, people, particularly if they hadn't received active cannabis types before, I find it very hard to distinguish. So, we thought that overall, when we looked at the data afterwards, we found that people were not very good at being able to distinguish what was placebo and what was not placebo. Now, if they had received it in the last session where they'd already received three active sessions, then maybe they would have some sense that they could sort of deduce that that may have been placebo. But if they'd received it earlier than that and people did find it quite hard to tell if it was placebo, active cannabis.
Trevor: OK, all right. So, the big reveal, you've had these people drive, they've had placebo, they've had high THC, high CBD and half and half CBD THC. How's their driving?
Dr. Arkell: So, I mean, we had a couple of major findings from this. The first one, I think perhaps the most relevant for medical cannabis patients in some sense, was that CBD didn't produce any driving or cognitive impairment. So, at either point in time, it either that 40-minute drive or that four-hour drive, there was no significant difference between a placebo and the CBD only condition in terms of driving or cognitive performance. If we looked at the THC conditions, we do see some impairment at 40 to 100-minute drive in both the THC and the CBD conditions. So, I think this is a really important point that suggests that adding CBD to THC doesn't have any sort of ameliorating effects. People often think that by adding CBD to you can reduce some of the impairment and the negative side effects. And we really didn't see that here at that level of driving impairment that we saw during that first drive, 40 minutes. It was very similar to what we'd expect to see in a driver with a blood alcohol concentration of 0.05 which is the legal limit here in Australia. And I know in a number of other countries around the world, I know in the US and I think in Canada it's a little higher.
Trevor: Yeah, I think we're point to 0.08 to North America.
Dr. Arkell: Right. OK, so it's, I suppose, similar to what we accept as legal level of driving impairment. So that's not extreme, but it's also not negligible. But by four to five hours that impairment had more or less disappeared. So this was really nice. This gave us some of the first evidence under real world conditions that the impairing effects of cannabis, at least insofar as they relate to driving, seem to have more or less one off by about four hours.
Trevor: And I really like that part. I want to come back to it because we do various continue education to all things cannabis. And one of the rules of thumb that keeps people keep repeating without evidence is, you know, so tell your patients that, you know, abstain from driving four hours after inflation, about six hours after ingestion and about eight hours if they experience euphoria. So, it's nice to hear you now have some evidence for that four hours part.
Dr. Arkell: Absolutely, yeah, I mean, and, you know, for some people that may be longer. I think this isn't a universal rule, but it gives a really nice sort of clue as to what's going to happen in the majority of people. You know, we had a couple of cases where people were still impaired at four to five hours and a couple of cases where people are probably fine to drive after, you know, after maybe three or four hours. But on the whole, it seemed that by four to five hours, people were more or less back to baseline. And in those cases where people were still a little bit impaired. The interesting thing is that they knew that and they tended to actually sort of overwrite their driving impairment. And in a real-life situation, they probably would have chosen not to drive. At least that's what we saw from the rating of how confident they were in their driving ability.
Trevor: Well, and that, I thought, was one of the really interesting parts. You know, it wasn't that surprising that the THC, sorry, the CBD wasn't a impairing, although nice to see some numbers to it. But I liked how you guys asked them basically, how do you think your driving ability is? Can you talk to us a little bit about that. When did they think they were driving well, when did they think they weren't driving well, in relation to where they correlated at all with how much THC they'd had or did they have no correlation, you know, did they know they were impaired? And if they said they were impaired, were they actually impaired?
Dr. Arkell: They did know they were impaired. And when they thought they were impaired, they were impaired. Yeah, exactly. That that's sort of the short answer to that. I think people were quite well aware of, you know, they weren't necessarily always acutely aware of their level of impairment. And if anything, they tended to overrate it. So they often thought they were more impaired than they really were. That was that was most evident during the first drive, 40 minutes, which is when people were most stoned. You know, most people in the THC and THC:CBD conditions rated their driving ability as pretty low. At that point. We had a few cases where people just flat out refused to drive. They said, I don't feel safe. I'm not getting in the car. One case where the driving instructor said, come on, you'll be OK. You get in there anyway. And the person, you know, it was a little bit sort of borderline about their ability to drive and their driving ability did actually seem sort of less than what it should be once they got in the car. So that driving test was terminated quite early on. So we had a lot of supposed assurance in this data that people were pretty good at being able to judge their driving ability.
Trevor: Well, and I also really like that part again, you know, this is not definitive, but that's always been the anecdotal forever, is that. People, when they have too much to drink, overestimate their ability to how well they can drive and people who have consumed more cannabis than they should underestimate their ability, that's kind of been folk folklore for a long time. It's nice to see, again, not definitive, but nice to see a little bit of evidence behind that that that I thought that was really cool.
Dr. Arkell: I agree. I think this does provide some really nice evidence for that. I think one important point to note is that with regular users or people that are using daily, that pattern of effects may be a little bit different. People that do use cannabis more regularly do tend to think that driving is less impaired than that. It may actually be. But when we're dealing with this population, with occasional users, this was a group of people that would rather not drive if they felt like it was going to be unsafe, which, like you say, is a very different sort of effect to what you typically see with alcohol, which often produces over impairment and overconfidence, particularly in young people who are already at risk when it comes to driving.
Trevor: OK, and you touched on a little bit, but the combination of THC and CBD seemed to make people, I don't know drive worse, but that that standard deviation of lateral movement, seemed to be higher in the in the combination one thing compared to THC alone. I don't know if that difference was significant. And they also the people reported that they felt that the cannabis was weaker. They didn't feel as impaired when they combined the THC and CBD. Any comments on that, on things that maybe we should watch out for in the real world?
Dr. Arkell: Yeah, this is an interesting one. Exactly. Like you said, people did feel a reduction in the strength of drug effect. And in a couple of those other measures, they felt a little bit less anxious in line with what we might expect when you add in CBD. But that didn't translate into any into any sort of negation of that driving impairment, which was really interesting. Now, that difference between THC and THC:CBD was not significant. So, people weren't significantly more impaired with the combination compared with THC alone, but they certainly weren't any less impaired. And this is something we saw in our previous simulator study as well. And we weren't sure if maybe this was just some noise or an artifact in the data. But we saw this here again, that that combination did actually increase be STOP more than just TCH alone. Now, the difference is pretty small. I mean, even the increase versus placebo sounds pretty small. You know, two and a half centimeters doesn't sound like a whole lot, but it is. It's more than what it sounds like. It's not really a reference to the absolute two and a half centimeter, you know, movement on the road. In terms of the real-world implications of that, I think it's important for people to understand that adding CBD or at least using a combination product may, I suppose, produce some slightly different subjective drug effects. It may produce a little bit less anxiety. It may make you feel a little bit less stoned or suddenly change the nature of the drug effect. But that doesn't seem like it's going to translate into any negation of real-world impairment. And I've heard this a lot. People do say that being in the US and Canada and going into dispensaries and just chatting with people and maybe trying to understand where this idea comes from. And people have often said, oh, you know, if you add CBD, it's going to do this and this or this combination strains going to do this and this compared to this high TCH strain. And so, I think this suggests that we probably need to be a bit cautious of that. And that's important to patients and consumers alike to realize that using a product containing both CBD and THC could produce a similar level of impairment to what you might get with a THC product, even though you might actually feel a little bit less stoned.
Trevor: Good, good to know the other, and this is just because it's twenty-nine, 2020 and this happens. So, you know, reading through the people that you lost to follow up, so you lost a couple people to follow up the covid-19 did you. Because you know it's 2020 and that's what happens.
Dr. Arkell: Yeah. I mean that the university had to shut down so we had a couple of people that could only participate. You know, I think we had some that had done to something done three sessions, but there was a university wide shut down and we couldn't we couldn't go on with the study, which was a real shame. But I think a lot of, you know, similar labs. We're in a very similar but.
Trevor: Oh, absolutely. So that's most of my questions. Anything. So most, a lot of our listeners are either patients or health care practitioners. Any sort of pearls of wisdom, clinical applications you think we can we can take from your study, you know, for the medicinal patient who you know, does need to drive to work or frankly, even for the occasional "I smoke on weekends," what should people sort of take, from your study when it comes to their driving?
Dr. Arkell: Well, I think the key thing is, if you're using a CBD based product, you're probably going to be fine to drive. You know, as you said before, we sort of assume that already a lot of people did. But, you know, we make policy decisions based on evidence. And I think this gives us some really nice data now that CBD based products are probably not going to produce any driving or cognitive impairment. For people using THC products. I think this provides some I suppose, some assurance that by four to five hours you're probably going to be OK to drive, like you mentioned before, with within just a product with our products, that duration of effects may longer. And so, I don't really want to comment on that. You know, we have to recognize that this was limited to vaporize cannabis. But I think using smoked or high-priced products, you're probably going to be all right to drive after four or five hours. But as always, you know, exercise caution. If you feel like you shouldn't be driving or you may still be impaired beyond that, then it's important to listen to that and recognize that people do respond differently to cannabis. I think and this may be relevant also, as I think there's another really important study that needs doing here and that's actually going into patients and looking at where the patients who are using, you know, prescribed cannabis product. They're stable on a certain dose. They're comfortable with its effects, you know, how is it affecting their driving? I think that's one thing that's really missing here. This was in healthy volunteers, people that are using cannabis occasionally. But we know people that use cannabis more frequently to become more tolerant to it's impairing effects. And it's possible that for some patients, you know, medical cannabis may actually offset some impairment, that the underlying condition may actually cause. If you take chronic pain, for example, it's conceivable to think that that by itself may be impairing someone's driving. And, you know, using opiate based painkillers could potentially be far more damaging than using cannabis-based products. I think this is one our research area that I would like to be involved in. I think that really needs some attending to is after this. Will, you know, we really want to know this and be able to give advice to patients. And to do that, we really need a study looking at real driving performance in patients who are using, you know, their own type of cannabis in their own dose, not a standardized dose that we've given in the lab.
Trevor: We would all love to hear the results of that study. So let's hope you get to do it. Sort of a legalish question. So right now, we have a blood alcohol concentration. We know how alcohol leaves the body. It's linear. We know an awful lot about how the amount of alcohol in your system relates to how impaired you are. We have laws that say, you know, if you have this much cannabis in your system, you can be arrested. But do you think we are a little way away from actually being able to say, if you have this much THC in your system, you're impaired? Is this going to be kind of an ongoing scientific legal battle over the next how many ever years?
Dr. Arkell: I think we're a long way away and I don't think we're ever going to get there. I don't think that's I don't think we're ever going to have an answer to that question. And people have been asking this for a while. And I think there's more and more consensus now in the scientific community that it's not a question that we're ever going to be able to answer. You know, we know that blood or saliva, THC concentrations just do not correlate with impairment. For a number of reasons. Some of those pharmacokinetic some that it really depends on the route of administration, you know, peak blood levels when you vaporize or smoke compared with when you use oral product are hugely different and you know, the difference is even more enormous, depending on what time since Drug Administration you actually measure them. And so, I think we're stuck with an issue where this probably isn't the best way to go about detecting drug impaired driving. Like you said, alcohol is easy with its linear kinetics. You know, we can we can say to someone, if you've consumed three standard drinks, this is how long you need to wait until you get below the legal limit. We don't have that with cannabis, and I don't think we have a will. So, this is a really tricky one that I know they're certainly grappling with in Australia at the moment, probably, if more also in the US and Canada where you have legal cannabis market is how do you go about detecting drivers who may or may not be impaired, but may still have small amounts of THC in their system, particularly for patients and medical cannabis user. I mean, this is where it really hits home. You might have someone that has low levels of residual THC in their blood, but they're absolutely fine to drive. Maybe they used the product the night before and this is in the morning and they driving to work. Maybe that's above the legal threshold, the amount of THC they have in the system, but they're fine to drive. And then, you know, conversely, you might have someone that's below the legal limit but is really stoned and probably shouldn't be driving. This is a really tricky one. I'm not sure we're going to get a nice answer to the question is there a number.
Trevor: You know what, you're not the only one who said that, but it is nice to hear that again from someone so knowledgeable. That is most of what I had. Did you have anything else you thought I was going to ask or wish I was going to ask about the paper or anything else cannabis related?
Dr. Arkell: No, no. And I think that covers it really well. Yeah, I think those are I think we should have gone over what I think is the most important points and takeaways for the study and how this may apply to patients. So I'm happy with that.
Trevor: So, thank you very much.
Dr. Arkell: Thank you very much for inviting me. I appreciate that.
Trevor: Kirk. I really enjoyed that interview. I think we'll be hard pressed to find that interviewee farther away from us because once you get farther away from Australia and start getting closer again. So, what did you think of Dr. Tom Arkell and putting stoned people behind the wheel of a car on a highway?
Kirk: Fascinating Trevor. Yeah, I, I sat here this evening and I was telling you I was watching the video and I thought, gee whiz, we should get our YouTube channel going. And I had this epiphany of how international this fella is. He's an Australian bloke. And I was going to say “good on ya mate, good on ya mate” to find this to find this interview, we have a young Australian PhD who is doing studies in Europe and talking about buying Canadian cannabis.
Trevor: Yeah. And he even stint in Colombia as a researcher there. Yeah, no, he's made his way around and when I tell people but this one I just lead with. So, there's this researcher who put people. Had them, I say smoke weed but vaporize cannabis and get behind the wheel of a car on a highway and drive a hundred kilometers. That kind of gets people's attention.
Kirk: No, no. Yes. That gets the layman's attention because you go I can be stoned and drive, but the scientists will say, well, where's the placebo? Where's the double blind? And this guy had the placebo. He did a double blind. Right. This is a double-blind recreational use of cannabis smoking. Now, why is it recreational and not medicinal?
Trevor: Well, I don't know if you want to why, but this was sort of what he started with. So they had to have them to see if I get all things right. They had to have some experience. He didn't want this would be the first time you ever used cannabis. I think the magic number was he views at least ten times, but you're using less than twice a week, I think was the magic numbers. So, they wanted to do recreational quote unquote, we 'll call it occasional instead of recreational, occasional users, because a couple of reasons. One is before getting into the study, they had to be off of all cannabis for a period of time as a couple of weeks that be much harder for a medical user and for a medical user, it would be hard for them to start at zero. That was the whole idea of being off of all cannabis for a couple of weeks. They want them to come into the study with THC blood level was zero. So that was my understanding why they started with occasional users. But he does want to he does want to do it again with the medical or we'll call it the everyday user, the medical patient.
Kirk: Well, yeah, that's what I got out of this as well, is that he wanted his participants, young university students, to have some understanding of cannabis so that they weren't overwhelmed by being, quote unquote, high. But he also figured that medicinal users, people that use it every day, are more comfortable being stoned and tend to be more cautious. So he didn't think that chronic users of cannabis would be a good a good sample because they'd be biased, which makes me think that the average chronic stoner on the highway is usually traveling around ninety five kilometers an hour.
Trevor: Well, I got that too, and I thought that was really interesting. But I caught the subtlety a little differently that the occasional user under underestimated how well they were driving. You know, they thought they were more impaired than they were. Where he wasn't sure in the chronic user, if you would get that. Now, that is just fascinating because, you know, that's a it's been a myth forever or whatever you want to call it, that too much alcohol and you think you're driving way better than you are. You underestimate your amount of impairment. And it's been a myth forever that if you are stoned, you you're too cautious. And that's basically what this study said. But I think he was also just not sure the difference in how impaired you were and how impaired you thought you were with occasional versus chronic. Like, I think that's probably another study.
Kirk: Yeah, yeah, the drunks, the drunks overestimated their skill and the chronic cannabis users, quote unquote, the stoners overestimated their skill and meaning that there are completely opposite. The drunks can drive and stoners can't. And but yet when they get the two behind the wheel, we know drunks can't drive, but yet the stoners does seem to be overcautious. The other thing I found interesting about this, this study is, again, there's these little nuances that come out of it and the whole concept of being greened out. We know that if you green out, meaning that you've got too much THC in your and your quote unquote, too stoned that taken some CBD will calm you down? Well, his hypothesis is that it might calm you down philosophically, internally. It might settle you emotionally, but from the skills of driving a vehicle not a hope in hell.
Trevor: So, I thought that was really fascinating to. Now Kirk, what did you think about placebo cannabis.
Kirk: Yeah, yeah. Yeah. You probed him on that. Isn't that interesting eh. They fake out the people to say that you're vaporizing cannabis that has no cannabinoids in it, just the Terpenes or the terpene-like-substances. So, I thought that was cool. That's what I said to you Trevor. We have here a double-blind placebo study on driving.
Kirk: And what I like about it is that it just creates more questions, but it substantiates. Say that for me. Substantiates.
Kirk: Yes. What we what we intuitively know. But I'm sure somebody will find a reason not to. Well, even the researcher found reasons not to, not to go full hand into this, but he offers us some very interesting insights to cannabis and driving and yes, to be on the European highway driving high. It's a cool study, Trevor. “Good on ya mate.’
Trevor: I really enjoyed it. And you can't we can't put too much into this good or bad, but we'll take homes. I really like this one. As we've been talking in these cannabis Continuing Education things and just talking to patients in general, you have sort of you know, as a clinician, it's nice to have rules of thumb. And one of the rules of thumb that I've been told that I passed on is, you know, try not to drive and I'll get you can tell me why this might not work for a medical patient a second. But the general rule of thumb is you tell people not to drive for hours after inhaling six hours after ingestion and eight hours if you feel or feel high. But and that at least that four hours inhalation, that went really well with the study. So there's some actual numbers to that rule of thumb.
Kirk: This study for a researcher, what does he got here? He's got an educated sample of people. So, he has chosen a solid sample of people who understand cannabis. Right. So they are people who understand cannabis. He's taken those people and given them for four exercises. That includes a placebo, CBD, CBD:THC and THC, right?
Kirk: He is given the metered doses, he's metered the doses to a vape. So one thing that didn't you didn't get on in the in the in the question in the interview, which I have to assume is that it must have been whatever it was fifteen milligrams of this and ten milligrams of that. I'm sure a meter, the grass everyone got the same cannabis. So, he metered the dosing. He metered the timing. He metered, the mileage. He needed to sway on the highway.
Kirk: This was probably one of the best studies that that that we can understand from the perspective of micro microscopic science. But behavioral sciences, this is a solid, solid study that only says we need to study it more.
Kirk: But the consequences the results are solid man. These are solid results.
Trevor: They are. And we should probably throw out one more highlight, because I think it's one of his big Take-Home thing. Oh, first, I should also mention so since I have it here in front of me, this wasn't just in any old run of the mill publication. This was in JAMA, the Journal of the American Medical Association. And we should probably mention the title, The Effect of Cannabidiol and Delta9 tetrahydrocannabinol, a driving performance, a randomized clinical trial. And so the CBD part. Another big highlight from this is CBD doesn't affect driving. Does not yeah, I know it's it shouldn't surprise anybody, but it's nice to have some numbers.
Kirk: In the transcript. That was my pregnant pause.
Kirk: you didn't give it to me of course. Of course, we know CBD doesn't affect driving. We know that from the research. But now we have clinical behavioral science that it doesn't affect driving.
Trevor: On a literal highway.
Kirk: This is a this is a wonderful, wonderful for Trevor. Again, man, I compliment you on finding this. It's a good, good piece of science. I like this interview. Yeah, well done.
Trevor: That was a lot of fun. I think I'll throw it to Renee again for the music. Anything else you need to sign us out with or tell people to look forward to coming up.
Kirk: I'm really excited about the Web page. We've invested some money into it and I think it's going to be a solid, solid destination where we have a potential of making every episode come alive. For our listeners, you can log on to our Web page. You'll listen to the you can listen to the podcast and you can research the papers that the authors are talking about. The guests are talking about. You can also read along. Yeah, I'm really excited about our Web page. So, yeah, I want everyone to know that eight weeks from now other than that, Renee, play us out. Find us some music.
Trevor: I'm Trevor Shewfelt, I'm the pharmacist.
Kirk: You are. I am Kirk Nyquist I'm the registered nurse and we are Reefer Medness - The Podcast, an international podcast.
Trevor: International. See you guys later.
Rene: All right, guys, that was great. So as far as a song for this episode goes, the first song that came to mind on the topic of Driving and Europe was Autobahn by Kraftwerk. And it happens to be one of my favorites. So I figured we would just play that. So enjoy.