Cannabis products are evolving, with new forms and formulas hitting shelves each year, and their average THC-level is rising in tandem.
A report on this new landscape and its implications, requested last year by Colorado’s General Assembly, was released by the Colorado Department of Public Health and Environment (CDPHE) on Monday.
The CDPHE’s Retail Marijuana Public Health Advisory Committee produced the report, which contains scientific findings related to “tetrahydrocannabinol (THC) potency of marijuana and any related health effects.” THC is commonly known as the cannabis compound, or cannabinoid, that produces the high associated with cannabis consumption.
Colorado joined Washington state in 2012 to become the first two jurisdictions in the world to fully legalize cannabis consumption and sales for adults. Since then, regulators from around the country and world have looked to these two states’ experiences, as they dealt with many cannabis-related regulatory hurdles for the first time.
The report, which focuses on THC rather than cannabinoids that appear in lower concentrations in the cannabis plant, lays out current scientific literature on “potential adverse health effects associated with high concentration THC products,” and points out where data is lacking. Finally, the report concludes with a number of recommendations aimed at education and harm reduction.
While a 2018 Colorado Market Size and Demand Update showed that cannabis flower “accounted for the majority” of all statewide cannabis sales, many plant extract products with stronger concentrations of THC also showed up on the legal market when sales went live in 2014. These products include liquids for vaporizers, edibles, tinctures, topicals, or other products like nasal sprays. Since sales went live, the report notes, adults have increasingly used different forms of cannabis consumption. For example, in 2018, “dabbing concentrates significantly increased.” Further, those who dabbed did so much more often than those who reported smoking, vaping, or consuming edibles. Those who used cannabis more often were also more likely to use more than one form of consumption.
“Six years after retail marijuana was legalized in Colorado, it is apparent that progress has occurred quicker in the marijuana industry than in science. The sheer quantity and variety of marijuana products available on the retail market place is proof of this rapid advancement,” the report concluded, noting that too few studies on the impacts of these products have been conducted. In addition, scientific literature on important areas of study, like cannabis consumption during breastfeeding and pregnancy, cardiovascular and respiratory effects, cancer, gastrointestinal effects, effects on reproductive health, as well as second or third-hand exposure, were limited, therefore preventing the report from successfully assessing the “full health impact” of higher concentration THC products.
Cannabis products are not only becoming more diverse in form, those newer forms often contain more THC than is found in flower. The report notes that flower on the market in Colorado averages 19.6% THC, while “some retail marijuana stores advertise up to 95% THC in concentrate products.”
Also, “literature shows a trend of increasing THC concentration happening worldwide and it appears to be increasing on a yearly basis.” The report highlighted a study that used cannabis samples confiscated by the Drug Enforcement Administration that showed that average THC content spiked from 6.7% in 2008 to 55.7% in 2017, “with fluctuation in between.” For comparison, the cannabis grown for research at the University of Mississippi for the National Institute on Drug Abuse averages just 4.14%.
Why all of this work on products containing more THC? One concern noted in the report, and based on available literature, is “substantial evidence that THC intoxication can cause acute psychotic symptoms, which are worse with higher doses.” These symptoms can include hallucinations, paranoia, and “feeling emotionally unresponsive.” The report highlighted a 2015 study that showed that people who consumed products containing more THC “had greater odds of developing first episode psychosis compared to those who never use marijuana products.” The report also found “moderate” evidence that people who consume cannabis with more than 10% THC concentration are “more likely than non-users to be diagnosed with a psychotic disorder, such as schizophrenia.”
The watershed 2017 National Academies of Sciences, Engineering, and Medicine’s comprehensive review on cannabis research parsed out the important distinction between “association” and “causation” between cannabis use and schizophrenia.
“What does the data support? Conclusions were that there is substantial evidence to support that cannabis use is associated with developing schizophrenia and other psychotic disorders. Associated. Not causation, but association,” Ziva Cooper, Research Director of UCLA’s Cannabis Research Initiative, told Cannabis Wire last year.
There is also a correlation between THC levels and continued consumption. Among those who said they used cannabis products with less THC, the “relationship was not maintained, signaling that higher THC concentration may be the catalyst for this relationship.” There’s also “moderate” evidence that children who consume cannabis products with more THC are “more likely than non-users to continue use.”
Colorado regulators decided in 2016 to limit the maximum concentration of THC products allowed in edibles to 10 mg of THC per dose, or 100 mg per entire product. As the report notes, “This change was prompted after public health concern was raised due to reports of THC overconsumption in adults and unintentional or accidental THC consumption by children.” For example, in 2015, the death of a 19 year-old made national headlines when he consumed six-times the suggested edible dose and plummeted four stories. In 2014, New York Times columnist Maureen Dowd published a widely discussed op-ed that delved into her negative experiences with a cannabis chocolate bar.
When it comes to reports of cannabis exposure to the Rocky Mountain Poison and Drug Center from January 2017 to June 2020, data show that children make up a sizable portion. For example, of the 973 total cases of cannabis exposure, 324 (36%) are for those aged 5 and younger. Those under the legal consumption age of 21 made up for 628 of the total 973 cases; and, within that, looking only at exposure to concentrates, 67 (68.5%) of 104 reports.
Separately on Monday, CDPHE released the Healthy Kids Colorado Survey for 2019, a biennial survey of Colorado middle and high school students. Among the findings: there were “significant changes” in how teenagers use cannabis since the first time surveyors asked high schoolers the question.
“While smoking marijuana remained the most frequent method of use in 2019, smoking decreased as dabbing significantly increased as the second most common method of marijuana consumption among high school students,” the survey noted. There were also “significant increases” in vaporizing cannabis.
The survey concluded that “these are concerning trends since marijuana products associated with these methods of consumption often contain high concentrations of tetrahydrocannabinol (THC), the primary psychoactive compound within marijuana.”
The report concluded with recommendations in three policy areas: education, research, and surveillance. On education, the report recommends education on THC concentration, as well as the possible mental health effects of cannabis products that contain more THC. Recommendations on research include the prioritization of studies on the effects of higher concentration THC products, their dosage, how often they’re used, and mental and acute health, as well as studies that use cannabis products from Colorado’s cannabis market. Finally, on surveillance, the report recommends that data be improved by collecting information on product type and THC content, and asking healthcare providers to do some of this gathering. The report also recommends that public health workers and regulators monitor both adverse reactions by product type, and the concentrations of THC in different products available to consumers in Colorado.
“Our ability to make unbiased, evidence-based statements on the potential health effects of marijuana products containing high THC concentration is limited until further scientific research can be conducted and the evidence shared or published. Therefore, in the best interest of public health, we suggest funding research to answer these questions,” the report concludes.