The latest in a string of studies to show that marijuana legalization does not lead to increased underage cannabis consumption has just been released.
“Our results suggest that adolescents’ marijuana use may not increase immediately following initiation of retail marijuana sales, which seems plausible given that they cannot legally access marijuana from the retail market,” concludes the study of Colorado teens, published in the journal Prevention Research last week.
“Overall, we did not find a significant change in the prevalence of adolescent marijuana use from shortly before to after the implementation of a recreational marijuana law in Colorado.”
Researchers from the University of Colorado, New York University, Johns Hopkins University and the Colorado Department of Public Health and Environment teamed up to compare data from youth drug use surveys from fall 2013, which was just prior to the start of legal marijuana sales, and fall 2015.
Frequency Of Use And Consumption At School Decrease
In addition to “an absence of significant effects for change in lifetime or past 30-day marijuana use,” the results also showed that teens reporting that they had used cannabis during the past month did so less frequently and that use on school properties declined.
“Among those reporting past 30-day marijuana use, there was a significant decline in frequent use (i.e., > 20 occasions of use in the past 30 days) and use on school property.”
Another significant change the study identified between the two time periods was a decline in perceived harm associated with cannabis use, but that was not accompanied with an increase in perceived ease of access to marijuana or any changes in perceived wrongfulness or perceived parental disapproval.
The findings bolster the position of legalization advocates, who have long argued that ending prohibition for adults and allowing them to buy marijuana in regulated stores that check the ages of their customers will not cause more young people to use cannabis.
“We did not find a significant effect associated with the introduction of legal sales of recreational marijuana to adults in Colorado on adolescent (illegal) use.”
Marijuana possession and home cultivation became legal in Colorado shortly after voters approved a legalization ballot measure in late 2012, prior to the first dataset in the study. Legal retail sales began on January 1, 2014.
The findings of the new research were consistent across demographic subgroups.
The researchers looked at “change in current marijuana use from 2013 to 2015 by school characteristic including school poverty, proportion of student enrollment that was Black or Hispanic, urbanicity of the school, and local policy regarding retail marijuana sales in 2015.”
“We did not find a statistically significant change in current marijuana use for any of these school characteristics.”
The study authors hypothesized that the decline in frequent cannabis use and use on school property is related to societal changes ushered in as part of legalization:
“It is not clear what accounts for this finding, but we suspect it may be related to the public discourse around marijuana policy leading up to and following the passage and enactment of…Colorado’s [legalization law] in 2012. Media coverage, school-based prevention programs, and public health and advocacy campaigns focused strongly on the potential negative impacts on youth during this time, and there was widespread agreement that the legal market should be inaccessible to adolescents… Therefore, it is possible that those adolescents who use marijuana had more received more attention from friends, parents, or school personnel and may have opted to use off-school grounds or less frequently. This interpretation may be further supported by the finding of an increase in perceived wrongness reported among current marijuana users.”
The findings add to a growing body of research showing that legalization is not associated with increased teen marijuana use.
A federal survey released late last year, for example, showed that rates of marijuana use among 8th, 10th and 12th graders is lower now that it was prior when to states began enacting legalization in 2012.
Another study looked at state-by-state youth use rates and found that state medical cannabis laws did not lead to increases.
The new study was supported with federal funding through the National Institutes of Health.
Photo courtesy of Carlos Gracia.
Smoking Marijuana Actually Improves Working Memory, Study Indicates
A new study contains a finding that runs counter to common stereotypes about marijuana and forgetful stoners: smoking cannabis actually seems to improve working memory.
Researchers at the University of Florida acknowledged that their study, which involved rats and was published in the journal Neurobiology of Learning Memory, was unique. Much previous research has concluded that cannabis impairs cognitive performance. But the same time, many of those studies didn’t involve actually inhaling marijuana smoke like this one did.
The team put the 32 rats (split evenly by gender) through a pair of delayed response tasks that involved either finding and pressing a lever a certain amount of times or poking their nose into a feeding trough a certain amount of times—the reward being food pellets, of course. The first few times, the rats were sober; in subsequent experiments, they were exposed to cannabis smoke.
“Cannabis smoke improved working memory accuracy. Placebo smoke did not affect working memory accuracy.”
For male rats, the marijuana didn’t seem to have any effect at all, but for female rats “exposure to cannabis smoke significantly enhanced choice accuracy,” the researchers wrote. That said, baseline performances (prior to exposure) were lower in females compared to males, which “raises the possibility that the enhancing effects in females were due to their relatively worse baseline performance rather than to sex differences in the effects of cannabis per se.”
“The overwhelming majority of research in both animal models and human subjects shows that acute administration of cannabis and cannabinoids induces deficits in tests of cognitive function, including working memory. In contrast, the current experiments show that acute exposure to cannabis smoke enhanced working memory performance in a delayed response task in rats, particularly in females in which baseline levels of task performance were lower than those in males.”
Nearby Marijuana Shops Make Homes And Rentals More Valuable, Studies Show
When a shop selling marijuana opens (or closes), there’s a direct impact on housing and rental prices in the surrounding area, according to a pair of recent studies.
Housing prices for new homes increase by 7.7 percent on average if they’re located within a quarter mile of a new dispensary.
A study published in the journal Contemporary Economic Policy evaluated how the price of new homes in Denver, Colorado, changes when a cannabis dispensary opens up nearby. Researchers compared the prices of homes before and after a dispensary opened within .25 miles, .25-.5 miles and .5-.75 miles.
When new dispensaries opened within .25 miles, housing prices jumped 7.7 percent on average. There was still a 4.7 percent increase for homes located within .5 miles, but the effect “disappears entirely” for houses that are further than .5 miles from a new dispensary. The researchers also found that the effect was slightly more pronounced if the dispensary was the first to the area.
“Our results suggest that despite potential costs, legalization is capitalized as a net benefit in housing prices,” the researchers wrote.
Interestingly, new dispensaries seem to have about the same impact on housing prices as new grocery stores, the study found. But the “mechanisms through which grocery stores affect housing prices are more obvious than dispensaries.”
“If public sentiment surrounding marijuana is positive, homebuyers may also prefer to select into neighborhoods with more dispensaries for convenience. Ultimately however, our data do not allow us to directly determine the underlying mechanisms driving this result, so these potential explanations should be considered speculative.”
Losing a marijuana coffeeshop causes a three percent decrease in Airbnb rental prices.
Amsterdam’s famous cannabis coffeeshops are known tourist attractions, but what happens when one shuts down? For his master’s dissertation, doctoral student Igor Goncalves Koehne de Castro identified at least one collateral effect: Rental costs on Airbnb drop by about three percent on average if the closure was within 250 meters of the lodging.
If the coffeeshop was further than 250 meters, rental prices didn’t change significantly.
There were plenty of examples for de Castro to study, which spanned from 2014 to 2017, because several coffeeshops have closed in response to new laws in recent years, including one in Amsterdam that prohibits the shops from operating within 250 meters of a school.
After controlling for other possible factors, de Castro developed a series of models based on Airbnb data on rental prices over time and their proximity to recently closed coffeeshops. The study revealed that these shops “present a positive impact” on rental prices for lodgings close to the shops—presumably because people who rent through Airbnb are “tourists” who are “sensitive to distances.”
“The findings of this study suggest that, for the city of Amsterdam, the de facto legalization of cannabis actually has a positive externality,” de Castro wrote. “This result puts new evidence to the debate of drug laws and policies, a matter that still lacks data and research.”
Photo courtesy of WeedPornDaily.
Vaporized Marijuana Produces A Stronger High Than Smoking It, Study Finds
Vaping marijuana gets you higher than smoking it, according to a new study published in an American Medical Association journal.
To test the difference, researchers started by recruiting 17 people who’d consumed cannabis in the past year but had abstained for at least the last month. Each individual participated in six sessions that lasted eight and a half hours—three where they smoked marijuana and three where they vaped it. There were three THC concentrations for both rounds of testing: 0mg, 10mg and 25mg.
After smoking or vaping, the participants were asked to fill out questionnaires to self-report their experience and then the researchers administered a series of physical and cognitive tests. Their blood was also subsequently analyzed.
The most obvious result was that when people smoked or vaped the 0mg control substance, it didn’t have a physical or psychological effect. But at 10mg—and especially 25mg—the participants got pretty stoned. They reported feeling hungry, sleepy and pleasant. Their mouths were dry. Some became anxious or paranoid. Three participants experienced adverse events like vomiting after consuming the 25mg cannabis.
Most regular consumers can probably attest to experiencing at least some of these things from time to time. But what might come as a surprise is that vaporized cannabis “produced significantly greater subjective drug effects, cognitive and psychomotor impairment, and higher blood THC concentrations than the same doses of smoked cannabis,” the study authors wrote in the paper published by JAMA Network Open on Friday.
In previous studies, researchers allowed participants to adjust their THC dose, which is likely why earlier results suggested that smoking got people higher than vaping. But when you hold the THC dose constant, vaping seems to be a more efficient delivery system, probably because smoking requires combustion that can deplete THC.
“Vendors and consumers of cannabis products should be aware that inhaling cannabis with a vaporizer could produce more pronounced drug effects and impairment than traditional smoking methods.”
That’s relevant information as the marijuana market continues to expand. More people are opting for vaporizers, and the study indicates that infrequent or new cannabis consumers should probably approach vaporizers with a bit more caution, start low and go slow.