Small doses of CBD appear to have no significant impact on driving, according to first-of-its-kind research published Tuesday in the Journal of the American Medical Association.
Similar doses of THC, meanwhile, were associated with short-term impairment “modest in magnitude and similar to that seen in drivers with a 0.05%” blood alcohol concentration, the study found. After about four hours, signs of marijuana impairment faded.
The University of Sydney-led experiment is the latest to study the effects of cannabis consumption on drivers, an issue of growing public concern as more jurisdictions around the world remove laws against the plant and its chemical components.
“The results should reassure people using CBD-only products that they are most likely safe to drive, while helping patients using THC-dominant products to understand the duration of impairment,” said Iain McGregor, academic director of the university’s Lambert Initiative for Cannabinoid Therapeutics.
The new research was funded by the Lambert Initiative, which studies the health effects of cannabis, and conducted at Maastricht University, in the Netherlands. Marijuana Moment reviewed a draft of the paper prior to its publication on Tuesday.
To measure the effects of the cannabinoids on drivers, researchers first had participants vaporize one of four cannabis blends: mainly THC, mainly CBD, a combination of the two cannabinoids or a placebo containing less than 0.2 percent total cannabinoids. The target dose for each cannabinoid other than the placebo was 13.75 milligrams.
Subjects then got into cars and took to the road. Accompanied by a licensed driving instructor, each completed a 100-kilometer circuit on a stretch of Dutch highway twice: first 40 minutes after consuming the cannabis blend and again four hours after consumption.
Researchers measured driving impairment by tracking how much drivers’ vehicles drifted in the lanes—a common metric known as standard deviation of lateral position (SDLP)—as well as fluctuations in vehicle speed. Participants were also tested in a laboratory setting for cognitive and psychomotor performance, blood cannabinoid concentrations and cardiovascular indicators such as heart rate and blood pressure.
Consuming CBD alone seemed to have little impact on performance.
“There were no significant differences between CBD-dominant cannabis and placebo,” the study says. “SDLP in the placebo and CBD conditions did not differ, indicating that CBD…did not impair driving.”
“These findings indicate for the first time that CBD, when given without THC, does not affect a subject’s ability to drive,” said Thomas Arkell, the study’s lead author.
Participants who consumed THC or a blend of cannabinoids, meanwhile, showed moderate but statistically significant impairment behind the wheel during their first test drive, posting SDLP numbers similar to drivers with blood alcohol concentrations of 0.05 percent. The study’s authors note the degree of impairment “is thought to indicate the lower limit of clinically relevant driving impairment.”
Unlike many drunk drivers, however, subjects who consumed THC or the THC–CBD blend seemed distinctly aware of their risk behind the wheel. That was true even as observable signs of their impairment faded.
Subjects described themselves as “significantly more impaired” after consuming THC or both cannabinoids, with a top complaint being decreased confidence. After the tests were completed, however, most subjects were able to correctly observe that their quality of driving itself was worse only during the first test.
“Participants considered their driving at 240-300 min to be significantly more impaired in the THC and THC/CBD conditions than in the placebo condition despite there being no difference across conditions in SDLP at that point in time,” the authors write.
The second test began four hours after consumption, which researchers say is about the time it seems to take for THC’s effects on driving to fade.
“Previous on-road and simulator studies have described increased SDLP for up to 3 hours following inhaled cannabis,” the study says. “Consistent with this, the present study failed to detect SDLP at 4-5 hours.”
That doesn’t mean consumers should necessarily assume they’re good to drive after just four hours. Higher inhaled doses or edible products, authors note, could extend the duration of impairment “and so these results should not be considered definitive.”
Similar limitations could apply to the study’s CBD findings. Authors note the 13.75 mg target dose in the study is considerably lower than what’s typically given in certain treatments, such as for pediatric epilepsy. “Driving outcomes may differ with higher CBD and THC doses and different CBD:THC ratios,” they write.
More fundamentally, the researchers acknowledge, the experiment could be failing to detect extremely minimal impairment caused by CBD. Confidence limits used in analyzing data from the 26-person experiment “suggested the possibility of subclinical impairment” too small to be measured in the study.
Nevertheless, the authors said, the findings offer valuable real-world data about how cannabis affects drivers—or, in some cases, apparently doesn’t.
“While some previous studies have looked at the effects of cannabis on driving, most have focused on smoked cannabis containing only THC (not CBD) and have not precisely quantified the duration of impairment,” said McGregor at the University of Sydney’s Lambert Initiative. “This is the first study to illustrate the lack of CBD effects on driving and to also provide a clear indication of the duration of THC impairment.”
Despite widespread concerns that relaxing cannabis laws could lead to more dangerous roadways, data on the subject has been largely inconclusive, allowing speculation to run rampant.
After evaluating available evidence last year, experts tasked by U.S. congressional lawmakers to look into the issue concluded that fundamental questions about THC’s impact on driving remain unanswered.
“Although laboratory studies have shown that marijuana consumption can affect a person’s response times and motor performance,” wrote the Congressional Research Service, “studies of the impact of marijuana consumption on a driver’s risk of being involved in a crash have produced conflicting results, with some studies finding little or no increased risk of a crash from marijuana use.”
The lack of clear evidence has frustrated both legalization opponents, who worry about increased highway dangers, but also medical marijuana patients who are at risk of arrest and conviction for THC-impaired driving even days after their medicine’s effects wear off.
In Pennsylvania, the House of Representatives approved a measure in October that would protect registered medical marijuana patients from being penalized under the state’s DUI laws.
“You can ask any veteran or anybody that’s using medical cannabis right now, if they took the prescription on Monday, [on] Wednesday, they’re not high,” Rep. Ed Gainey (D) said in a floor speech before the vote. “And if they got pulled over, they darned shouldn’t be charged for being intoxicated or under the influence of medical marijuana.”
Photo courtesy of the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney
Legal Marijuana States See Reduced Workers’ Compensation Claims, New Study Finds
Legalizing marijuana for adult use is associated with an increase in workforce productivity and decrease in workplace injuries, according to a new study partly funded by the federal government.
In a working paper published by the National Bureau of Economic Research, researchers looked at the impact of recreational cannabis legalization on workers’ compensation claims among older adults. They found declines in such filings “both in terms of the propensity to receive benefits and benefit amount” in states that have enacted the policy change.
Further, they identified “complementary declines in non-traumatic workplace injury rates and the incidence of work-limiting disabilities” in legal states.
These findings run counter to arguments commonly made by prohibitionists, who have claimed that legalizing marijuana would lead to lower productivity and more occupational hazards and associated costs to businesses. In fact, the study indicates that regulating cannabis sales for adults is a workplace benefit by enabling older employees (40-62 years old) to access an alternative treatment option.
“We offer evidence that the primary driver of these reductions [in workers’ compensation] is an improvement in work capacity, likely due to access to an additional form of pain management therapy,” the study, which received funding from the National Institute on Drug Abuse, states.
The implementation of adult-use legalization seems to “improve access to an additional channel for managing pain and other health conditions, suggesting potential benefits on populations at risk of workplace injuries,” it continues.
The study is based on an analysis of data on workers’ compensation benefit receipt and workers’ compensation income from
2010 to 2018 as reported in the Annual Social and Economic Supplement of the Current Population Survey.
“Our results show a decline in workers’ compensation benefit propensity of 0.18 percentage points, which corresponds to a 20 percent reduction in any workers’ compensation income, after states legalize marijuana for recreational use. Similarly, we find that annual income received from workers’ compensation declines by $21.98 (or 20.5%) post-[recreational marijuana legalization]. These results are not driven by pre-existing trends, and falsification exercises suggest that observing estimates of this magnitude is statistically rare.”
Researchers said that they’ve found evidence that cannabis use increases post-legalization among the age cohort they studied, but no such spike in misuse. Further, they found a decline in post-legalization prescriptions for medications used to treat chronic pain, indicating that some people are using marijuana as a substitute for traditional painkillers.
“We hypothesize that access to marijuana through [recreational marijuana laws] increases its medical use and, in turn, allows better management of symptoms that impede work capacity—e.g., chronic pain, insomnia, mental health problems, nausea, and so forth,” the study says. “Chronic pain management is likely to be particularly important in our context as this is the health condition most commonly reported among medical marijuana users.”
Beyond decreasing workers’ compensation claims and costs, legalization also is a boon to the economy by adding jobs in legal states.
The cannabis industry added more than 77,000 jobs over the past year—a 32 percent increase that makes the sector the fastest in job creation compared to any other American industry, according to a report released by the cannabis company Leafly last week.
Starting A Business? Study Finds Marijuana May Help—And Hinder
A new study out of Washington State University suggests cannabis may inspire entrepreneurs to come up with big, bold business ideas—but could also lead them down a rabbit hole of wishful thinking.
Researchers found that entrepreneurs who were frequent marijuana consumers came up with business pitches that were more original but less feasible, according to a panel of experts who scored the ideas.
“Beyond their innate creative aptitude, entrepreneurs may attempt to enhance their creativity,” says the study, which will appear in the March 2021 issue of the Journal of Business Venturing. “Despite generating more original ideas, we found that cannabis users’ ideas were less feasible.”
Also important variables, the study found, were an entrepreneur’s passion, which may heighten creativity at the expense of feasibility, as well as their past entrepreneurial experience, which tended to increase idea feasibility but rein in creativity.
The findings “provide insight into the creative benefits and detriments associated with being a cannabis user,” the study says, “suggesting that cannabis users—especially those who are passionate about exploring new venture ideas or those with relatively little entrepreneurial experience—may benefit from non-users’ insights to develop the feasibility of their ideas.”
To test the effects of marijuana on business-idea generation, researchers had 254 entrepreneurs come up with “as many new venture ideas as possible” based on virtual reality—a prompt provided by researchers. Participants had three minutes to generate ideas, then selected the idea they believed to be their best. Two “expert raters” then evaluated the chosen pitches for originality and feasibility.
Reachers say their findings support one of the study’s core hypotheses: that there are differences between how cannabis users and non-users arrive at business ideas. “Cannabis users are more impulsive, disinhibited, and better at identifying relationships among seemingly disparate concepts,” the study proposes. “However, these differences and cannabis users’ diminished executive functioning likely detracts from idea feasibility.”
Notably, the researchers did not ask participants to consume marijuana in the study setting itself. Rather, to compare cannabis-users to non-users, researchers split participants into two groups: those who had used marijuana less than five times in their lives and never in the past month (non-users) and those who’d consumed more than five times in their life and at least twice in the past month (users).
“Unlike alcohol, where health organizations have established standards for heavy drinking,” the study notes, “scholars have yet to reach a consensus on what constitutes a cannabis user versus a non-user.”
Because the study was merely observational, it also cannot determine whether marijuana use was in fact the cause of the differences between the two groups’ ideas. It may be that some other trait or traits explain both a person’s idea generation and their decision to consume cannabis.
The study’s cannabis user group comprised 120 people, or 47.2 percent of all participants. Researchers attempted to control for certain other factors, such as gender, age, education and technological familiarity.
While the findings suggest that, overall, cannabis can both inspire originality and limit feasibility, the outcomes were influenced strongly by what researchers described as “entrepreneurial passion for inventing” as well as their “entrepreneurial experience.”
“Cannabis users’ diminished idea feasibility compared to non-users was significant in those with low entrepreneurial experience,” the study’s authors wrote, “but not in those with high entrepreneurial experience.”
Similarly, “cannabis users’ lower idea feasibility was signifiant at high entrepreneurial passion for inventing but not low entrepreneurial passion for inventing,” the study found.
“Entrepreneurial passion for inventing appears to play a role in channeling cannabis users toward idea originality but away from idea feasibility,” it says. “Conversely, entrepreneurial experience appears to attenuate the positive relationship of being a cannabis user with idea originality and its negative relationship with idea feasibility.”
As the study itself acknowledges, many successful business leaders and visionaries have credited the inspirational powers of cannabis. Apple luminary Steve Jobs, for example, “noted that his use of cannabis helped him feel ‘relaxed and creative.’” (Biographer Walter Isaacson also quoted Jobs as saying another drug, LSD, was “one of the most important things in my life. … It reinforced my sense of what was important—creating great things instead of making money.”)
On the other hand, researchers argue that cannabis use can be a double-edged sword. “Regular cannabis use is associated with numerous detrimental effects, such as the potential for dependence and addiction, risk of motor vehicle accidents, mental and respiratory health problems, as well as memory and other cognitive impairments.”
Benjamin Warnick, assistant professor at Washington State University’s Carson School of Business and lead author of the study, said in a press release that the research is “the first study we know of that looks at how any kind of drug use influences new business ideation,” adding that “there is still much to explore.”
“Clearly there are pros and cons to using cannabis that deserve to be investigated further,” Warnick said. “As the wave of cannabis legalization continues across the country, we need to shed light on the actual effects of cannabis not only in entrepreneurship but in other areas of business as well.”
Photo courtesy of the Drug Policy Alliance, Sonya Yruel
Areas With More Marijuana Dispensaries Have Fewer Opioid Deaths, New Study Finds
Increasing access to marijuana dispensaries is associated with a significant reduction in opioid-related deaths, according to a new study.
“Higher medical and recreational storefront dispensary counts are associated with reduced opioid related death rates, particularly deaths associated with synthetic opioids such as fentanyl,” the paper, published on Wednesday in the British Medical Association journal’s BMJ, concluded.
It’s a finding that “holds for both medical and recreational dispensaries,” the study says.
Researchers looked at opioid mortality and cannabis dispensary prevalence in 23 U.S.states from 2014 to 2018 and found that, overall, counties where the number of legal marijuana shops increased from one to two experienced a 17 percent reduction in opioid-related fatalities.
Increasing the dispensary count from two to three was linked to an additional 8.5 percent decrease in opioid deaths.
Further, the study found that this trend “appeared particularly strong for deaths associated with synthetic opioids other than methadone, with an estimated 21 percent reduction in mortality rates associated with an increase from one to two dispensaries.”
“If consumers use cannabis and opioids for pain management, increasing the supply of legal cannabis might have implications for fentanyl demand and opioid related mortality rates overall.”
“While the associations documented cannot be assumed to be causal, they suggest a potential association between increased prevalence of medical and recreational cannabis dispensaries and reduced opioid related mortality rates,” the researchers wrote. “This study highlights the importance of considering the complex supply side of related drug markets and how this shapes opioid use and misuse.”
This is far from the first piece of research to draw a connection between legal cannabis access and reduced harms from opioids. Multiple studies have found that marijuana effectively treats conditions like chronic pain for which opioids are regularly prescribed, and surveys show that many patients have substituted addictive painkillers with cannabis.
“Cannabis is generally thought to be a less addictive substance than opioids,” the new study says. “Cannabis can potentially be used medically for pain management and has considerable public support.”
“Given the alarming rise in the fentanyl based market in the US, and the increase in deaths involving fentanyl and its analogs in recent years, the question of how legal cannabis availability relates to opioid related deaths is particularly pressing.”
“Our findings suggest that increasing availability of legal cannabis (modeled through the presence of medical and recreational dispensary operations) is associated with a decrease in deaths associated with the T40.4 class of opioids, which include the highly potent synthetic opioid fentanyl,” it continues. “This finding is especially important because fentanyl related deaths have become the most common opioid related cause of death.”
Earlier this month, a separate study determined that medical cannabis use is associated with significant reductions in dependence on opioids and other prescription drugs, as well as an increase in quality of life.
These studies could also provide valuable context to a federal health agency in the U.S. that is conducting a review of studies to learn if marijuana and kratom could potentially treat chronic pain with fewer side effects than opioids.
Photo courtesy of WeedPornDaily.