UW ADAI - Symposium - 2022 - Short and Long-Term Risks of High THC Products
(September 16, 2022)

Friday September 16, 2022 10:30 AM - 12:30 PM Observed
University of Washington - Addictions, Drug, and Alcohol Institute (UW ADAI) - Logo

The University of Washington Addictions, Drug, and Alcohol Institute (UW ADAI), formerly the Alcohol & Drug Abuse Institute, is a multidisciplinary research institute at the University of Washington. UW established ADAI in October 1973 as a research institute for alcohol and drug use research at the university and in the northwest region. Grants and contracts from federal and state agencies and private foundations provide the majority of the Institute’s funding, which includes appropriations from the state’s Dedicated Marijuana Account.

Agenda

  • Introductions: Lauren Davis, Washington State Representative
  • ModeratorTracy Klein, WSU CCPRO Assistant Director
  • Julia Dilley, UW
    • "High THC Products: Public Health Outcomes in Legal Markets"
  • Carrie Cuttler, WSU
    • "Acute Effects of High Potency Cannabis Flower and Concentrates on Cognition"
  • Jason Kilmer, UW
    • "Cannabis Use by Young Adults: Trends and Considerations"
  • Deborah Hasin, Columbia University
    • "Cannabis Use and Psychiatric Comorbidity: Epidemiology and Association with High-Potency Cannabis Products"
  • Rosalie Pacula, University of Southern California
    • "Recommendations for Regulating High Potency Cannabis in Recreational Markets and Why"

Observations

A researcher suggested changes in availability and acceptance of high THC products contributed to increased use by adults and youth, and gave ideas for monitoring and reducing this trend.

Here are some observations from the Friday September 16th University of Washington Addictions, Drugs, and Alcohol Institute (UW ADAI) 2022 Symposium on “High-THC Cannabis in Legal Regulated Markets.”

My top 3 takeaways:

  • Dilley shared a presentation on "High [tetrahydrocannabinol] THC Products: Public Health Outcomes in Legal Markets," surveying both youth and adult cannabis consumption patterns and poison center cases involving cannabis products (audio - 18m, video).
    • Dilley kicked off her presentation at the symposium by telling attendees that she’d speak “about high THC products from a public health lens and especially from the perspective of the data that we can access readily within public health systems.” More specifically, she planned to interrogate how “a legal cannabis market [may] affect consumption of high THC products in populations, and health and safety outcomes.” She credited the prior speaker, Jonathan Caulkins, Professor of Operations Research and Public Policy at the Heinz College of Information Systems and Public Policy at Carnegie Mellon University (CMU), for the “foundational information” about policy options to reduce availability and use of the products to “protect public health and mitigate harms.”
    • Leveraging data from “public health surveillance systems or data that we can access,” Dilley acknowledged that some sources of information “don't include any information about specific products.” Additionally, she was “going to focus mainly on pre-[coronavirus] pandemic data periods.”
      • Her first source was sales and licensing data from cannabis regulators when stores began opening in July 2014. She indicated “it took a few years for the market to get up and running” but there were “400 or thereabouts retailers that are operating within the state and that's been holding fairly steady.” Compared to other early states to legalize like Alaska, Colorado, and Oregon, Washington had “fewer per capita cannabis…retail licenses operating,” observed Dilley.
      • She noted that “the proportion of sales that are for higher THC products, like concentrates and edibles, increases as a share of the market over time” since 2014. Mirroring trends mentioned by Caulkins, cannabis flower remained the dominant product type.
    • To evaluate consumption behavior, Dilley used the Behavioral Risk Factor Surveillance System (BRFSS), an “ongoing telephone survey of adults” used to “monitor all kinds of health behaviors,” along with HYS statistics, “one of the leading school-based health surveys in the United States.”
      • She felt that “the most important thing to take away is that the percentage of adults” consuming “cannabis in the past 30 days” had been increasing over time between 2012, when Initiative 502 was passed, and 2019, going from eight percent to 17%.
      • In 2015, BRFSS included a question about what type of cannabis adults were consuming each month, Dilley explained. The data showed less flower consumption, going from 85% “down to 70% in 2019,” and increased use of edible and vapor products, which “went up from 17% in 2015, up to 27% in 2019.”
      • Parsing HYS data for trends in youth cannabis use was more “complicated” for Dilley, who said that “for today, just assume it's kind of a flat line.” Like BRFSS, HYS questions had been expanded to ask minors “how did you usually use” cannabis products, she mentioned, and showed a similar “drop in the percentage of kids who said they're usually smoking it, and then modest increases in” use of vapor and edible or infused beverages between 2014 and 2018. Cannabis “dabs,” were added in 2018, Dilley remarked, and a “fairly high percentage of kids are saying they use dabs.” 
        • On May 31st, Segawa’s briefing on 2021 HYS results revealed a “pretty substantial decrease” in cannabis use by youth in the 30 days preceding their survey by three percent of 8th graders, seven percent of 10th graders, and “16% of 12th graders.” Question changes and survey gaps from the pandemic had broken the trendlines used by officials, however the 2012 HYS factsheet for cannabis—the last survey prior to cannabis legalization in the state—showed cannabis use rates for 8th, 10th, and 12th graders had been at nine percent, 19%, and 27% respectively.
      • Dilley told attendees that 2021 HYS results were similar to youth survey data from Oregon, which also showed that “Oregon's 11th graders…went from 93%” cannabis smoking in 2017, “down to 80% of kids in 2019.” Over this time she pointed out that “kids who use cannabis who said they vaporized it went from 11% up to 44%.” While the question format and grades surveyed weren’t an exact match, she commented that HYS data indicated similar changes in behavior. 
    • For adults living “living in communities where a cannabis retailer opens less than 0.8 miles from their zip code area, the current use of cannabis increased, and…frequent use increased,” she stated, while those “more than 18 miles away…don't seem to have any change in their cannabis use pattern.” Dilley claimed that “we saw something similar with youth” use. Retail stores near their home allegedly led youth to “perceive cannabis as more easy to get,” she said, “and they also change or become less prevention motivated in terms of believing that cannabis use is wrong for them or thinking that their friends believe it’s wrong, and thinking that parents think it's wrong, and thinking that adults in their community think it's wrong.” Dilley’s conclusion was that “the presence of the markets can have an effect on adult and youth behaviors.” With these datasets, Dilley reported that “data for both adults and youth” reflected “patterns of cannabis use and how those have changed as local area cannabis retailers open up.” She acknowledged that “one caveat is we've only been looking at this for cannabis products overall not by specific product type, but that's certainly our next research agenda item.”
    • “We're fortunate to have data available from U.S. poison control centers,” reported Dilley, as they were a “data source that contains information about cannabis product types.” She said calls could be made by individuals “experiencing symptoms” and wanting “to get help from a toxicologist or a nurse consultant” or from healthcare facilities that “don't know what to do about a specific exposure.” Dilley argued this information amounted to a “canary in the coal mine" and hypothesized wider problems in consumption by the general population. Acknowledging “people have become more accustomed to” searching the internet for information, she assumed they were less likely to call poison centers. Therefore, when Dilley heard “a signal coming through poison centers, I'm taking them very seriously.”
      • Evaluating nationwide poison center data on cannabis reports over time, she’d divided them between “plant based” cannabis flower and products like edibles and concentrates. Like other sources, this information was “showing that total cannabis exposure have gone up over time…​​from 2017 to 2019” and that what had been “driving that upward trend are these manufactured products, with edibles making up the greatest proportion of those.”
      • Falling into a seasonal trend of police and media sensationalism around finding cannabis in Halloween candy, Dilley described people “getting into cannabis infused edibles during Halloween and maybe getting those confused with their Halloween candy.” Analysis of “seasonal patterns of reported edible exposures by age group,” in both legal and non-legal cannabis states found “edible exposures increase about 25% among children under 10, 22% among youth ages 11 to 20, but it's during that November/December, versus the other month so…Halloween is at the beginning of that period,” however cannabis exposure “really continues throughout the holiday season.”
      • Dilley pointed out that in 2017, WSLCB officials were “getting concerned about child exposures for edibles” and expanded packaging and labeling rules for edibles to feature a Not For Kids logo, “kind of a like a Mr. Yuk type sticker” that included the phone number for the Washington Poison Center (WAPC). She was also happy about having servings of edibles individually wrapped, “so, if this were to be out on a table and a toddler got into it, they might get into the outside bag, but then they have to get into the second packaging within the inside bag.” Comparing the impact of this change to other states with cannabis markets, she said researchers focused on “those exposures that had significant health outcomes because we wanted to screen out people who just called more often because the poison center phone number was on the package.” Dilley suggested that researchers wanted to isolate “serious exposures that we thought probably would have been called in any case” to interpret revised labeling as contributing to “a 25% reduction in edible poisoning reports for children under 10, 51% reduction for ages 10 to 20, and a 23% reduction for adults 55 and older.” Besides helping youth, she theorized that “maybe that packaging also communicates to adults and helps adults…titrate their own dose more effectively.”
      • WAPC and other poison control centers are private, nonprofit entities which provide a public health service to those contacting them, and also maintain partnerships with academic, healthcare, and prevention interests. It’s Cannabis Observer’s understanding that privileged access to poison center data is reserved for selected researchers; whereas, in our experience, we were asked to pay significant fees.
    • Considering potential policy responses to the increased use of high THC products, Dilley advocated for assorted “regulatory stuff we can do.”
      • Dilley suggested revising regulations around “what can be sold, the potency of those products that can be sold, purchasing limits, maybe times of day, different places, price incentives, and Dr. Caulkins talked about taxing as a good thing, and then promotion.” She noted there had been “fewer limits on advertising early on in the legal market” and mediums for cannabis retail like billboards and sign spinners had been banned in law and rule. It was “a good example of where regulation maybe didn't directly address THC concentration” but helped limit messaging on that “approach of getting high.”
      • Furthermore, Dilley suggested “health care and behavioral health systems may need support for their screening processes and intervention processes for people that they're helping.”
      • She felt that because “we're seeing these changes in youth consumption patterns, maybe we need youth-centered social marketing campaigns and safe storage campaigns maybe with a seasonal emphasis.” Educational efforts like this “may need policies to make sure that those get out there.”

A WSU researcher described results of two studies she conducted on cannabis consumption and memory, sharing that her hypothesis on the impacts of concentrates hadn’t been validated.

Here are some observations from the Friday September 16th University of Washington Addictions, Drugs, and Alcohol Institute (UW ADAI) 2022 Symposium on “High-THC Cannabis in Legal Regulated Markets.”

My top 3 takeaways:

  • Cuttler presented “Acute Effects of High Potency Cannabis Flower and Concentrates on Cognition,” her research with subjects who independently purchased cannabis products and consumed them while video conferencing as a workaround to federal restrictions before completing various cognitive tests (audio - 22m, video
    • Cuttler established that adults stopping by “one of the hundreds of cannabis dispensaries serving our state…would see that they carry an enormous variety of high potency cannabis products, including cannabis flower that typically exceeds 20% [tetrahydrocannabinol] THC, edibles sold in 10 milligram (mg) doses in our state, tinctures that you can place under your tongue, lotions you can apply to your skin, suppositories that I won't further describe, and cannabis concentrates that I will further describe.” She suggested that “research has focused almost exclusively on the effects of cannabis flower and edibles. There has been an absolute dearth of research examining the effects of all these other products, including cannabis concentrates.”
    • “Now as their name implies cannabis concentrates are a highly concentrated form of the drug,” stated Cuttler, “typically produced using chemical solvents like butane, and the end product is an oil, wax, or resin-like substance.”
      • Such products “typically have over 60% THC, but can also exceed 90% THC,” she continued, reporting that more than “half of cannabis users say they have used concentrates and 13 to 37% report using them on a regular basis.”
      • She pointed to research, Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state, showing concentrate sales “increased by almost 150% while flower shares in our state showed a slight decrease” in the first 18 months of legal retail in Washington.
        • The study, which was initiated in October 2014, stated that after the nearly 150% increase in concentrates, they comprised 21.2% of the market. Part of this increase may be attributed to limited product choice during the initial months of retail operations before cannabis concentrates became more widely available.
      • The increase in concentrate sales made some people “very concerned because we know that higher doses of cannabis increase the detrimental outcomes of cannabis use so we assume that higher potency versions of the drug will also increase these detrimental outcomes,” said Cuttler. She understood this concern was part of why the symposium had been organized.
    • Study of high concentration cannabis products had been hindered by the plant’s federal Schedule I status, explained Cuttler, as it “imposes numerous legal restrictions and hurdles that have impeded research.”
    • Cuttler reviewed recent THC Lab research with graduate students Emily LaFrance and Aria Petrucci attempting to “examine which aspects of cognition are detrimentally affected by the chronic use of these high potency cannabis products” along with “whether concentrate users would demonstrate objectively worse cognitive test performance than exclusive flower users.” She relayed the “inclusion and exclusion criteria” for her participants, including the type and frequency of cannabis products used, their overall physical health, and they “couldn't be heavy drinkers or smokers.”
      • Cuttler said their study “recruited 98 non-users and 100 cannabis users that met these criteria,” with 46 using cannabis flower only, and “54 reported using both flower and concentrates regularly.”
      • Participants were “well balanced with respect to gender, but…predominantly White and young” with the “average age around 24” though “both groups of cannabis users report[ed] lower levels of education than non-users…there were no other significant group differences, and I statistically control for these differences in education in the upcoming results.” They completed a 90 minute “battery of cognitive tests in the controlled laboratory environment while sober,” she commented, and were asked “to try to remember to rate how difficult they found each test immediately after completing” them. “They were told they wouldn't be reminded to do this, it'd be up to them to do this on their own,” she added, and the same went for requesting “their $50 compensation towards the end of the study.”
      • Cuttler’s study found “both groups of cannabis users performing worse than non-users, and the difference between flower users and concentrate users” wasn’t significant. This pattern continued in a verbal memory test, which she said involved “both the immediate and delayed recall trials of this test” and “the difference between the concentrate and flower users is not significant.” Concentrate consumers did score worse than flower and non-consumers in a “simple episodic recall” test which asked “participants to briefly describe each of the tests that they had to complete at the end of the study,” Cuttler added. Finally, flower consumers scored worst at “the incidental recall trial of the digit symbol substitution test…and now the concentrate users are not significantly different from either of the other two groups.”
      • Her study found “no significant effects of regular use of high potency flower or concentrates on measures of visual spatial memory, temporal order memory, source memory, working memory, or three different measures of executive functioning.” Cuttler also believed this to be “the first study to attempt to examine the chronic effects of cannabis on either temporal order memory or source memory.” And “most critically, we found no significant differences in the performance of the groups who reported the exclusive use of flower relative to the group who reported using both flower and concentrates. Thereby providing no real evidence for the notion that regular use of concentrates is associated with worse cognitive outcomes, than exclusive use of flower,” she explained.
    • LaFrance and graduate student Amanda Stuber had joined Cuttler in another research effort “to examine the acute effects of high potency cannabis, which we defined as having at least 20% THC, on prospective, source, false, and temporal order memory as well as non-normative decision making.” This involved a comparison of “cannabis concentrates to cannabis flower and we also wanted to compare the acute effects of cannabis flower with CBD, to flower without CBD, to see if it actually might be protective,” she stated.
      • They had avoided “all of the legal restrictions on acute cannabis research by having participants purchase and administer their own cannabis in their own environment off federal property while we simply observe them over Zoom video chat,” which Cuttler said amounted to “an observational field experiment.” She stressed that she and her research team “didn't purchase the drug. I didn't administer. I didn't even touch the drug. We just observed [a federally] illegal act.” Cuttler said participants were “randomly assigned to purchase and use one of three different product types” and researchers “compensated participants for their time, but not their cannabis purchase, using Amazon gift cards because at least as of today, you can't buy cannabis on Amazon.”
        • The preparation section of the study elaborates that “Those in the three cannabis-using groups were informed that we are interested in studying the effects of specific products and were sent a list of products available at local recreational cannabis dispensaries that met criteria for the group to which they were assigned (e.g., participants randomly assigned to the THC flower group were emailed a list of pre-rolled joints with ≥ 20% THC and 0% CBD available at local dispensaries). Prior to testing, participants in the cannabis-using groups purchased a product off the list using their own funds.”
        • Consumption methodology stipulated that “Participants in the three cannabis-using groups were asked to show the researcher the cannabis product they purchased for the study. The brand, strain, and cannabinoid content (%THC and %CBD) were recorded. The vast majority of participants used the list they were sent to purchase the product-type to which they had been randomly assigned to use.”
      • She briefly addressed participant criteria of being “very healthy, [they] couldn't use other drugs, couldn't be heavy drinkers or smokers, couldn't be breastfeeding or pregnant” and “had to report that they had never previously experienced any adverse events with cannabis” and had previously consumed “both concentrates and flower.” 80 people were found that fit this standard, conveyed Cuttler, with 20 being assigned to flower, concentrates, and products containing THC and CBD categories, along with “a sober control group.” On the day of the tests, the “average period of abstinence” for subjects who would consume cannabis products on camera “was closer to 24 hours.”
      • For cannabis products containing CBD, they required at least 0.7% of the cannabinoid. Although “we initially aimed for way higher level” of the compounds, “it proved exceptionally difficult to find in such high potency flower,” she acknowledged. The researchers “recorded the number of puffs participants took and we time the durations of their inhalations and holds, and we found that participants randomly assigned to use an extremely high potency concentrate took significantly fewer puffs than those smoking flower joints,” Cuttler said. She reported this enabled subjects to achieve the same “subjective high as those inhaling high potency flower…with no significant differences in the intoxication ratings of any of the three cannabis used in groups at any time.”
      • There “was a medium-sized effect with the participants who smoked the joint containing both THC and CBD recalling significantly fewer pictures than the control group,” she commented, and a source memory evaluation showed “THC flower and concentrate groups had worse source memory for pictures.” A false memory test described by Cuttler “found a medium size affected group on free recall with participants who smoked a joint containing both THC and CBD once again having worse free recall” and “all three cannabis using groups had more false memories…relative to the sober control group.” She told attendees “we found no significant effects” on “two tests of prospective memory, a couple measures of temporal order memory, and four measures of non-normative decision making” cautioning that “we might have been underpowered to detect some of these effects.” Cuttler concluded that their tests ”found no significant differences between the performance of those who are randomly assigned to use cannabis flower relative to those who were assigned to use a concentrate.” She further speculated this “failure to detect effects on these domains of cognition may pertain to our use of highly experienced cannabis users” as “it's apparent that some people will habituate to some of the effects of cannabis over time.”
      • The research offered no evidence “that CBD offset the detrimental effects of THC. In fact, the group that smoked the joint containing both THC and CBD had more memory impairments than the group that smoked just the THC flower joint,” Cuttler indicated. She expressed some surprise that “one of the most important and encouraging findings from these studies is the lack of evidence that cannabis concentrates are more detrimental to cognition than flower. This was not my hypothesis.” She claimed there had been “a lot of speculation that concentrates would magnify the harms of cannabis. My studies instead indicate that neither the chronic use of concentrates, nor acute intoxication on concentrates is worse for cognition than flower” as consumers chose to “self-titrate their use of extremely high potency concentrates.”
  • Cuttler responded to several attendee questions related to cannabis dosage, compensatory effects, studies of specific cultivars, and THC tolerance.
    • “High potency consumers seem to self-titrate. Were you able to estimate the actual THC dose by the puff/inhale/hold times in any way?” (audio - 1m, video)
      • Cuttler said they hadn’t been estimating that as it was a “hard thing to catch here in such a naturalistic setting over Zoom.”
      • Prior research indicated “there was little evidence that response to marijuana was a function of breathhold duration.”
    • “How much do you think your findings on acute memory effects were due to compensatory behavior in consumption of the different forms of cannabis?” (audio - 1m, video)
    • “Most of the cannabis research has been focused on THC concentration, has there been any significant studies on how different cannabis strains affect different cognitive effects and lineages?” (audio - 1m, video)
      • Cuttler replied that she’d been interested in addressing the “common folklore propagated by budtenders” that “everything is a hybrid nowaday.” Her study had focused on levels of THC and CBD, but she hoped to “do research on some of the minor phytocannabinoids. We're doing a study right now looking at the effects of cannabigerol (CBG) because we do think that some of these are going to produce different effects.” She doubted that “we're going to see much of this on cognition specifically” as she was certain it was “THC that is implicated in the cognitively impairing effects of cannabis.”
    • “The [Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition] DSM-5 diagnostic criteria for cannabis use disorder (CUD) has to do with increased…THC tolerance and dependence. Is there any inclination…or intuition that the use of high potency products indicates higher THC tolerance and may predict some level of dependency?” (audio - 2m, video)
    • Cuttler believed that “higher potency versions of the drug are more likely to increase” risks of dependency, and that those with CUD would be “more likely to use higher potency versions of the drug.” She felt this made any “cross-sectional survey looking at this and linking the two is problematic because there’s a huge chicken-and-egg problem here, and probably a bi-directional relationship.”

A presentation on consumption habits among young adults in Washington described negative health effects, poor academic outcomes, and suicidal thoughts attributed to cannabis use disorder.

Here are some observations from the Friday September 16th University of Washington Addictions, Drugs, and Alcohol Institute (UW ADAI) 2022 Symposium on “High-THC Cannabis in Legal Regulated Markets.”

My top 3 takeaways:

  • Three questions from attendees elicited comments from Kilmer on youth access, product theft from retailers, and suicidal ideation for young adults.
    • “Given the conversation that we've had and the restrictions that the retailers have about selling to youth, we also heard some information about perhaps theft of products as being one venue of access for youth. How do you suggest that we address the problems of youth access?” (audio - 2m, video)
      • Kilmer’s perspective was that “parents have to be part of…prevention” as surveys were indicating 18-20 year olds’ access was increasing partially from “parents, with their permission.” He felt parents were “operating off of an old script and your parent says ‘I used when I was younger; I turned out fine.’ They used different stuff.” Kilmer hoped parents were “aware of how truly influential they are” and “aware of impacts on mental health and academic outcomes.”
    • Cannabis Observer founder Gregory Foster asked, “You indicated that the [WYAHS] data that you presented for 2020 and 2021 showed a theft from dispensaries or stores as a means of obtaining cannabis products and that that increased from zero to low levels…the question is if that survey distinguishes between cannabis products obtained from regulated retail stores versus hemp derived intoxicating products” from stores lacking cannabis licensure or age restrictions on their premises (audio - 1m, video)
      • Kilmer responded that the increase in thefts were “significant largely because it had been zero every other time point,” but the survey “did distinctly ask about retail stores.”
      • Cannabis Observer was not able to locate the survey to report how this particular question was framed to respondents. We asked because the timing closely matches more widespread availability of products like delta-8-tetrahyrdocannabinol (delta-8-THC or D8) and corresponding consumer interest in the products.
    • “Is there any research suggesting that the risk of suicidal thoughts among cannabis consumers is higher among 21 to 25 year olds?” (audio - 1m, video)
      • Feeling that this could be “an important research question,” Kilmer wasn’t aware of “anything with the focus solely on that older part of the young adult age group.”

A research analysis portrayed cannabis consumption, particularly among youth, as one of the top “environmental factors that need to be considered” in mental health policymaking.

Here are some observations from the Friday September 16th University of Washington Addictions, Drugs, and Alcohol Institute (UW ADAI) 2022 Symposium on “High-THC Cannabis in Legal Regulated Markets.”

My top 2 takeaways:

  • Hasin spoke about "Cannabis Use and Psychiatric Comorbidity: Epidemiology and Association with High-Potency Cannabis Products" and emphasized meta-analyses framing cannabis as a risk multiplier for mental health problems (audio - 18m, video, presentation)
    • “I'm going to be presenting to you today on cannabis use and some issues with psychiatric comorbidity,” established Hasin, who acknowledged that “I was originally asked to limit the talk to the effects of cannabis potency and the risk for psychosis, but it became clear in looking into that that a broader topic was needed.”
    • Beginning with “measurement issues in general for cannabis,” Hasin contrasted “alcohol where…a general marketing policy” created understanding about “how much alcohol is in beer and wine and hard liquor. There is such a thing as a standard drink where you can really ask people about a standard drink and compute how much ethanol they're consuming.” She recognized that “not everybody in a survey will know what a standard drink is, but when you're conducting the survey you can present them with enough information that they can give you more accurate answers about how much alcohol they're consuming.”
      • However, the “picture’s really very different for cannabis,” Hasin reported, elaborating that “in Washington state, people know more about what they're using and what the potency is and the quantities because of the way the market has evolved here in terms of how it's sold.”
      • She felt that research on consumption showed “across the country, there's wide differences by state and when you look across time.” Hasin brought up “older studies” focused on “lifetime-ever use, how often do they use, but that's about as far as they [go] in terms of quantifying use.”
      • Hasin asserted “there have been studies that show that consumer knowledge of [tetrahydrocannabinol] THC levels in the products that they use is pretty low,” leading to “a challenge to figure out the relationship between anything other than ever used or not, and psychiatric outcomes.”
        • While consumer knowledge of other cannabinoids, terpenes, terpenoids, flavonoids, and compounds present within cannabis products may be similarly low—in part due to required packaging and labeling emphases on THC and cannabidiol (CBD) content---a similar lack of awareness and curiosity about the diversity of cannabis product constituents appeared to be prevalent among the research community represented at the UW ADAI Symposium. THC—and merely delta-9-THC—occupied nearly all attention to the exclusion of more nuanced research agendas.
    • Contemplating “state laws and cannabis potency,” she compared her study of access to high cannabinoid concentration products with prior speakers.
    • Hasin wanted to address “mental disorders and conditions” including those “other than psychosis.” She shared a series of prior studies finding “a statistically significant increase risk across all of these studies” that cannabis use in adolescence was associated with increased odds of depression and suicidal ideation/attempts. However, she hadn’t seen “a statistically significant increase in the risk for anxiety disorders.”
    • Turning to the topic of psychotic episodes and psychosis, Hasin first “talk[ed] about that relationship regardless of potency.” She commented that there’d been “a lot of interest in these topics” and enough studies completed that “meta-analyses are really how one needs to look to see aggregated results and what they add up to.”
      • The analyses Hasin presented covered both studies about cannabis and psychotic symptoms, as well as diagnoses of the condition, and “across all of these studies, with varying levels of strengths of the relationship, as cannabis intensity exposure increases so does the risk for this psychotic disorder.” Using a forest plot, she believed the studies demonstrated “quite a substantial effect for the use of cannabis and the risk for these psychosis outcomes.”
      • For individuals “that already have a diagnosis of psychosis,” Hasin attested that other studies had shown “an increased risk for poor outcome among the patients who continued to use cannabis.” She referenced a study of data from the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) she’d worked on which had “Self-reported psychotic disorders by past-year cannabis variables (non-medical use)” for 2001-2002 and 2012-2013. Noting a condition “was only considered positive if the psychotic disorder had been diagnosed by a doctor or another medical professional,” Hasin told attendees the data showed a “statistically significant increase in psychosis between the two studies” for non-medical cannabis consumption. This would mean “as the level of cannabis intensity increased, there was an increasing risk for the self-reported psychotic disorders,” she said, rising prior to legal cannabis sales beginning in 2014. Hasin estimated that those meeting the criteria of cannabis use disorder (CUD) had their chances for psychosis “increased by about five-fold.”
      • Looking at information from Denmark, Hasin described “a psychiatric register where everyone that's treated in…any type of medical setting gets added to the register. So, it's possible to track psychiatric disorders over time,” she commented, and “over a period when cannabis use increased in Denmark, these researchers looked at…what happened to rates of cannabis induced psychosis using the registry data.” She relayed their findings that incidences of both psychosis and schizophrenia had gone up over the same period.
    • Hasin next discussed “the topic that I was originally asked to speak about, which is cannabis potency and the risk of psychosis.”
      • Highlighting a 2015 study out of the United Kingdom, she said researchers there classified “different types of cannabis use including one kind called ‘skunk’ which was known as being a higher potency type of cannabis,” though “if you look at how skunk was defined…by today's standards That's not particularly high potency at all.” Researchers had looked at first “incidents of psychosis” using a “carefully matched set of community controls,” she revealed “the prevalence of any lifetime cannabis use was pretty similar in the psychotic patients and in the control group, suggesting that there was no particular risk from any lifetime cannabis use.” However, Hasin remarked that those favoring “skunk” strains, “were much more prevalent in the group of psychotic patients than they were in the community controls, suggesting that there was risk that was conferred by using skunk…and using skunk every day really had the largest increase in odds.”
      • In 2019, researchers replicated the study in other countries, and “we see a pretty pronounced difference for using the high potency form between the case groups,” she added, and those using the “more highly potent form of THC daily were at the greatest risk.”
      • Hasin mentioned “discussion of all of these relationships by geneticists who posed the possibility that maybe there was a common genetic variant that gave rise both to cannabis use and a psychosis. This led to a lot of discussion and a lot of studies.” Her conclusion was that questions about genetic predispositions to cannabis or psychosis needed “an acknowledgment that psychosis is a complex condition. There are a lot of genetic and environmental factors, but it seems clear that cannabis use is one of those…environmental factors that needs to be considered.”
    • Hasin concluded that “it's entirely safe to say that cannabis use is highly associated with increased risk for psychotic disorders and increased risk for relapse.” Moreover, she informed the group that since “most research on the effects of cannabis potency was conducted during years when high potency cannabis was pretty weak by today's standards…it's reasonable to conclude that today's very high potency cannabis products might confer even greater risk for psychosis.” Hasin observed that “although psychotic disorders are fairly rare in the general population, they are very debilitating disorders, and very burdensome to patients, and their families, and to society as a whole.” She found there could be a public health justification limiting “marketing of very high potency cannabis products in ways that can be done effectively.” Believing that “cannabis use is widely seen as harmless by the general population,” Hasin called for new studies “in today's settings where people would be able to say more about what they were using, how often they were using, and what the potency was.” This could be a way “to really see what's going on with these relationships” in the current “cannabis landscape,” she added.

Engagement Options

In-Person

UW Tower, Brooklyn Avenue Northeast, Seattle, WA, USA

The symposium will be held in the Auditorium on the "M" floor.

Public Transportation: The UW Tower is located directly across the street from the University District light rail station. There are also a number of bus routes that serve that area of the U. District as well.

Parking: Parking for visitors of the UW Tower is available in the W46 garage, which is located on 12th Ave. Vehicles can enter and exit this garage from either 12th Ave NE or the alley between 11th and 12th. Self-pay machines are located on Level 4. The cost for parking is $18.75 daily ($4 hourly).

Information Set