A recent analysis of popular marijuana strains revealed widespread “genetic inconsistencies” that raise questions about what consumers are really getting at their local dispensaries.
The study, released last week, looked at 122 samples of 30 common cannabis strains, obtained from dispensaries in multiple cities around the United States. It turns out that strain names don’t appear to be reliable indicators of a given product’s actual genetic profile.
That might strike consumers as surprising, especially considering the fact that commercially available cannabis products are often reproduced through cloning and “stable seed strains.” Even so, the researchers found “evidence of genetic variation…indicating the potential for inconsistent products for medical patients and recreational users.”
While the study’s findings might disappoint recreational users who studied up on a strain’s reported effects on sites like Wikileaf, it poses a particular issue for medical marijuana patients who seek out specific strains to treat various health conditions, the researchers noted.
The factors behind the unreliability
The fundamental problem in cannabis strain inconsistency is that marijuana is federally illegal, limiting research and regulatory opportunities, and there’s currently no industry-wide system “to verify strains,” the study authors wrote. Therefore, “suppliers are unable to provide confirmation of strains.”
“Exclusion from protection, due to the Federal status of Cannabis as a Schedule I drug, has created avenues for error and inconsistencies.”
“Without verification systems in place, there is the potential for misidentification and mislabeling of plants, creating names for plants of unknown origin, and even re-naming or re-labeling plants with prominent names for better sale. Cannabis taxonomy is complex, but given the success of microsatellites to determine varieties in other crops, we suggest the using genetic-based approaches to provide identification information for strains in the medical and recreational marketplace.”
Hezekiah Allen, executive director of the California Growers Association, told Marijuana Moment that he agreed with that recommendation.
“We have been calling for an industry wide science-based system for several years,” he said, citing a legislative accomplishment in 2016 that mandated the California Department of Food and Agriculture “establish a process by which licensed cultivators may establish appellations of standards, practices, and varietals applicable to cannabis grown” in the state.
“Having universities finally able to engage in this type of research is one of the most exciting outcomes of legal reform,” Allen said. “This is an important step the multi-year effort to document and catalog the extensive culture of cannabis.”
“We envision a well informed market, where consumers ask questions before making a purchase. How is grown? Where is it grown? What type was grown? The answers to all of these questions hold great promise for humanity.”
In the new study, which was not peer-reviewed, the researchers at the University of Northern Colorado also pointed out that increased cross-breeding on cannabis strains (hybrids) has contributed to genetic inconsistencies.
“The results are clear: strain inconsistency is evident and is not limited to a single source, but rather exists among dispensaries across cities in multiple states.”
It’s not just the strains that showed genetic variation. The study also indicated that the cannabis categories “indica,” “sativa” and “hybrid” may be unreliable.
“If genetic differentiation of the commonly perceived Sativa and Indica types previously existed, it is no longer detectable in the neutral genetic markers [the researchers used],” according to the study. “Extensive hybridization and selection has presumably created a homogenizing effect and erased evidence of potentially divergent historical genotypes.”
The team’s findings are consistent with a 2015 study published in the journal PLOS ONE, which also analyzed the cannabis genetics and determined that “marijuana strain names often do not reflect a meaningful genetic identity.”
Youth Marijuana Treatment Admissions Fell After Legalization, Study Finds
Does legalizing marijuana for adults lead to a tidal wave of teens going to treatment? Not according to a new study out of Temple University, where researchers in fact found decreases in youth admission rates for problem cannabis use in two legal states.
The findings, published this month in the journal Drug and Alcohol Dependence, run counter to speculation from legalization opponents, law enforcement and some public health experts, who have warned that relaxing cannabis laws could lead to an explosion in cannabis use disorders among children. If that’s happening, the study found, treatment admissions data so far show no sign of it.
Examining data from publicly funded substance use treatment facilities, researchers from Temple’s geography and urban studies department, found that youth treatment admissions rates for cannabis use disorder fell sharply between 2008 and 2017, nationally as well as in Colorado and Washington State, which both passed legalization laws in 2012.
“Our results indicate that [recreational marijuana legalization] in Colorado and Washington was not associated with an increase in treatment admissions,” the study concluded. “Rather, we observe a substantial decline in admissions rates across US states, with evidence suggesting a greater decline in Colorado/Washington following RML as compared to non-RML states, though this difference was not significant.”
Co-author Jeremy Mennis, a Temple professor, told Marijuana Moment that the “national decline is pretty dramatic,” noting that on average, youth admissions rates for marijuana fell by nearly half.
“It declined more in Colorado and Washington, but the difference between them and other states was not statistically significant,” he said.
In other words, at least so far, legalization doesn’t seem to have made a particularly big impact on youth admissions rates one way or the other.
“Adolescent treatment admissions for marijuana use did not increase in Colorado and Washington following [recreational marijuana legalization].”
“The admissions rate is initially higher in Colorado/Washington at the beginning of the study period,” Mennis and co-author Gerald Stahler wrote, “but declines more rapidly following [legalization] as compared to the other states.”
As the study notes, if legalizing cannabis for adults were to increase the prevalence of cannabis use disorder among youth, “one potential consequence would be an increased need for treatment.” But that increased need hasn’t been reflected in actual admissions rates.
Still, the researchers are quick to caution that a drop in treatment admissions doesn’t necessarily mean a decrease in problem marijuana use.
“We’re not sure whether cannabis use disorder is declining or just treatment admissions are declining” for some other reason, Mennis said.
Youth cannabis consumption in the U.S. “has not substantially increased over the last 10 years,” he said, but it’s not drastically fallen, either. Yet since about 2011, treatment admissions have steadily declined.
Why the drop in admissions rates? “I don’t know why,” Mennis acknowledged. “This is speculative on my part.”
One possibility is that changing attitudes toward the potential dangers of marijuana have shifted in recent years, making individuals and their loved ones less likely to seek treatment.
“The perception that using marijuana is harmful has declined across the U.S. among youth and adults,” Mennis said, “and this may affect how people view whether their marijuana use is problematic or requires treatment.”
If fewer parents see cannabis as a harmful drug, for example, “they’re probably a lot less likely to see the use of marijuana among their kids as warranting treatment,” he said. “That’s a possibility.”
Reduced stigma around cannabis generally could also be playing a role, he said, with parents perhaps less likely to refer their kids to treatment for simply experimenting with the drug absent other problems connected to such use.
Perhaps the worst-case scenario, the paper says, is that the need for treatment still exists but somehow isn’t being met:
“If [cannabis use disorder] remained stable following [recreational marijuana legalization], or increased, as recent research indicates, the dramatic decline in adolescent treatment admissions we observe in states enacting [recreational marijuana legalization] would suggest an increase in unmet need for treatment, i.e. it may be the case that admissions rates are falling because an increasing proportion of adolescents with CUD are not entering treatment.”
“Cannabis use disorder is a thing, and I think a lot of people are resistant to the idea that it can be a thing. The question is whether cannabis use disorder is actually decreasing,” Mennis said. “If cannabis use is staying the same, then there’s a bigger and bigger gap.”
Studies on cannabis use disorder have arrived at mixed conclusions about whether it’s becoming more or less common as legalization spreads to more states. A study published last year found that, contrary to the expectations of some health experts, the prevalence of cannabis use disorder among frequent cannabis users has actually decreased in recent decades.
Cannabis use disorder “decreased significantly across all ages reporting daily/almost daily cannabis use between 2002-2016,” that study found. “Cannabis dependence prevalence decreased for adolescents and young adults and was stable only among adults ages 26+ reporting daily/almost daily cannabis use.”
Photo courtesy of Martin Alonso
Federal Agency Wants Help Developing A Standard THC Dose For Marijuana Products
A top federal health agency is requesting input on a proposal to establish a standardized dose of THC in marijuana products to ensure consistency among studies into the potential therapeutic benefits and risks of cannabis.
In a notice published by the National Institute on Drug Abuse (NIDA) on Monday, the agency said that little is known about the impact of varying THC potency, and creating a standard unit could help resolve that issue. That said, the notice acknowledges that marijuana contains other compounds that could complicate any standardization, in addition to problems arising from differing methods of consumption.
Even so, “such a unit is critical for conducting rigorous cannabis research,” NIDA said.
“Recognizing that a perfect measure may not be attainable at the current time, NIDA still believes that a standard dose would improve measures of outcomes in relation to exposure; and thus, could inform policy and public health strategies around cannabis use,” the notice states, adding that the agency is looking into a five milligram THC dose as the standardized unit.
Request for Information (RFI): Inviting Comments on the Establishment and Implementation of a Standard Unit Dose of Delta-9-tetrahydrocannabinol (THC) for Cannabis Research https://t.co/RkSzihPpbP
— NIH Funding (@NIHFunding) March 23, 2020
NIDA Director Nora Volkow discussed the importance of establishing such a unit in commentary published in the journal Addiction last month.
Citing research that calls for a five milligram THC standard, Volkow said she agreed with the study’s conclusion despite complicating factors. Those factors include potential issues related to the effect of having cannabis products with the same THC level but different concentrations of other cannabinoids such as CBD.
Also, varying routes of administration could present problems in ensuring research consistency. It’s unclear how the effects of a five milligram THC unit would differ between marijuana products consumed via smoking, vaping, edibles or topicals.
The notice also calls for information about labeling requirements for cannabis products. But while that might aid in observational or epidemiological studies, a federal standard for labels wouldn’t be achievable as long as marijuana remains a prohibited substance. The Trump administration’s secretary of health and human services talked about this problem as it applies to warning labels last year.
The complexities in research beyond having a standardized measure of THC “hardly negate the value” of setting one, Volkow said in her commentary. “In fact, having and using such a standard is a prerequisite for comparing the effects of various cannabis products on THC bioavailability, pharmacokinetics and pharmacological effects, which is knowledge fundamental to studies pertaining to medical use of cannabis.”
“Although cannabis remains an illicit substance in the United States, the expanded legalization by states requires us to develop the knowledge base that can help states develop policies to minimize risk from cannabis exposures, such as limits on the THC content of cannabis products,” she said.
Due to the lack of standardization, she said that studies often show conflicting results when it comes to questions about how cannabis impacts brain development and mental health conditions, for example. There’s also a lack of consistency in research comparing the effects of high THC and low THC marijuana.
In the study Volkow references, the authors said they examined “experimental and ecological data, public health considerations and existing policy” to determine that five milligrams of THC should be the standard unit.
The director said in her commentary that in spite of the “multiple caveats and complexities, the use of a standard unit dose of THC in research is an important step for improving our ability to understand the effects of cannabis in the population.”
NIDA’s notice calls for e-mailed submissions from “the scientific research community and any other interested parties” by May 1.
Volkow has been vocal about the importance of streamlining and improving research into cannabis, and she’s laid partial blame for the the lack of studies on marijuana’s restrictive federal classification.
While it remains to be seen when that fundamental impediment will be resolved, the Drug Enforcement Administration did announce last week that it is proposing a rule that would enable it to expand the number of authorized cannabis manufacturers for research purposes.
Photo courtesy of Martin Alonso.
Legalizing Marijuana Increases Housing Prices, Study Finds
So much for “there goes the neighborhood.” A new analysis suggests that states that legalize marijuana actually see a boost in housing prices, with the effect most pronounced once nearby retail outlets open for business.
Economists at the University of Oklahoma attempted to tease out the impact of adult-use cannabis legalization by examining listings on Zillow.com and tracking them against legalization in Colorado and Washington State. Their findings suggest legalization “has beneficial spillover effects at both the state and local levels,” casting doubt on the parade of horribles sometimes warned of by law enforcement and other critics.
“Concerns about the potential effect on crime rates and the difficulty in policing impaired driving have been cited as reasons to slow-walk the path to full recreational legalization,” the study’s authors write. “This research contributes to the discussion, providing evidence that recreational marijuana legalization (RML) has large positive spillover effects on the local housing market.”
Specifically, neighborhoods in Colorado and Washington saw a 7 percent price increase as marijuana retailers there opened shop, the study, which was published online this week by SSRN, found. “Considered together, this research suggests that there are second order benefits associated with marijuana legalization that policy makers and voters should be aware of when deciding the drug’s legal status.”
“Once recreational marijuana becomes available to buy easily at a dispensary and tax revenue is generated, there is significant home price appreciation.”
It’s not the first time researchers have looked into the effects of legalization on nearby home values. In 2018, researchers at Colorado State University found that home prices within a half mile of a retail cannabis store went up by 7.7 percent. A 2017 study, “Contact High: The External Effects of Retail Marijuana Establishments on House Prices,” found an 8 percent increase in the value single family residences that were “close to a retail conversion,” or store opening, compared to homes that were farther away. A 2016 analysis had similar findings, concluding that “legalization leads to an average 6% increase in housing values, indicating that the capitalized benefits outweigh the costs.”
The new study takes the past findings and pulls them into sharper focus. It concludes that legalization tends to impact the values of more-expensive homes differently than less-expensive ones, though homes of all price levels saw increases. The study also identifies variables that may work to lift residential property values in states that legalize, such as increased tax revenue to fund schools.
“Marijuana’s liberalization provides a novel source of tax revenue which states have used to fund capital expenditures, especially in education and it acts as an amenity via the dispensaries that distribute it,” the paper says. “The creation of a new legal market has direct implications for the local economy, as it establishes new dispensary jobs and reduces arrest rates. All of these factors have well-established impacts on housing markets.”
One of the analyses performed by the researchers found that prices among more expensive homes increased immediately following a successful ballot drive to legalize marijuana. Meanwhile, homes in less-expensive areas didn’t see much of a price increase until cannabis stores actually began to open.
As they describe it, the economists found “positive effects in the top of the distribution following the success of the ballot measure legalizing recreational marijuana, but no effect in the lower half.”
“The greatest impact occurs once it becomes legal to sell marijuana, with large positive effects across the price distribution, especially in the middle three deciles,” they write. “Heterogeneous responses to a policy shock have not been well-researched in the housing literature, making the findings here one of our major contributions.”
Legalization itself led to “positive effects upwards of ten percent in the top half of the price distribution,” the study says, “and between five and fifteen percent across the distribution after the state enacts the ballot initiative and the first legal sales take place.”
Why the lopsided effect? The economists say a number of mechanisms could be at work, with a big one being access to liquidity among the rich: “The wealthiest households can more rapidly move to (legal) states if they believe there to be some positive spillovers from legalization.”
The researchers attempted to address some confounding variables in their analysis, such as by assessing house prices by square foot rather than taking each property as a whole. “Geographic heterogeneity in our sample suggests that simply using house price as the dependent variable could bias the results since treatment homes are in high-price states,” the authors write. “By using house price per square foot as the dependent variable, we can ensure that this potential source of bias is accounted for.”
They also took particular note of when stores actually opened. “If the primary mechanism in our cross-state models is the economic development effect,” the study says, “then it is possible that the impact is only felt once the first dispensaries open and a large volume of marijuana sales take place, thereby generating tax revenue.”
“[W]hen a dispensary opens nearby, homes closest to it appreciate in price the most. This is consistent with our interpretation that new dispensaries act as amenities in the local housing market.”
One big question the researchers still can’t answer: Will it last? “Without the benefit of foresight,” they write, “our research is not able to determine whether the positive effect will persist.”
Other big unknowns remain, such as whether the effect was due to more people immigrating to the state after legalization, which would mean states that legalize later could see a diminished effect.
But for now, the effect is robust. And from what the researchers can tell, people don’t just seem to want the benefits of legal marijuana. They also want marijuana stores themselves to be near their homes. When the economists modeled home prices by distance to the nearest outlet, the data “show price appreciations for homes as the distance to the nearest dispensary decreases.”
“This demonstrates that [it is] not simply the benefits of increased tax revenue, but also the existence of the dispensaries themselves, that is driving the price increases,” the researchers found. “The dispensaries act as commercial amenities that the public puts a premium on being nearby.”