Association of Naturalistic Administration of Cannabis Flower and Concentrates With Intoxication and Impairment

Dyadic cannabis use, alcohol use and relationship satisfaction: A daily diary study

OBJECTIVE

Intimate relationships are important contexts for understanding individuals' substance use patterns and trajectories. Using a dyadic daily diary design reporting over 14 consecutive days, the present study examined the association between cannabis use, alcohol use, and momentary relationship satisfaction among adult couples METHOD: Eligible individuals on Prolific were invited to participate. We identified 33 couples where both partners participated. Participants completed a baseline survey and a 14-day daily diary study assessing their daily cannabis use, alcohol use, and relationship satisfaction. Multilevel modeling was used, within an Actor-Partner Interdependence Model (APIM), to evaluate the individual and interactive effects of one's own use and their partner's use on relationship satisfaction RESULTS: Significant actor and partner effects of alcohol and cannabis use were found using both baseline and daily report data. For individuals who use cannabis more heavily among sampled couples, cannabis and alcohol co-use was associated with reduction in their own next-day relationship satisfaction while alcohol-only use was significantly associated with increased next-day satisfaction. There were no significant effects of one's own or their partner's effects for individuals who use cannabis more lightly.

CONCLUSIONS

Findings replicate and extend prior research by demonstrating the dynamic nature of dyadic substance use and highlighting the unique impact of alcohol and cannabis co-use on daily relationship functioning.

Sex Differences in the Neural and Behavioral Effects of Acute High-Dose Edible Cannabis Consumption in Rats

The consumption of Δ9-tetrahydrocannabinol (THC)- or cannabis-containing edibles has increased in recent years; however, the behavioral and neural circuit effects of such consumption remain unknown, especially in the context of ingestion of higher doses resulting in cannabis intoxication. We examined the neural and behavioral effects of acute high-dose edible cannabis consumption (AHDECC). Sprague-Dawley rats (six males, seven females) were implanted with electrodes in the prefrontal cortex (PFC), dorsal hippocampus (dHipp), cingulate cortex (Cg), and nucleus accumbens (NAc). Rats were provided access to a mixture of Nutella (6 g/kg) and THC-containing cannabis oil (20 mg/kg) for 10 minutes, during which they voluntarily consumed all of the provided Nutella and THC mixture. Cannabis tetrad and neural oscillations were examined 2, 4, 8, and 24 hours after exposure. In another cohort (16 males, 15 females), we examined the effects of AHDECC on learning and prepulse inhibition and serum and brain THC and 11-hydroxy-THC concentrations. AHDECC resulted in higher brain and serum THC and 11-hydroxy-THC levels in female rats over 24 hours. AHDECC also produced: 1) Cg, dHipp, and NAc gamma power suppression, with the suppression being greater in female rats, in a time-dependent manner; 2) hypolocomotion, hypothermia, and antinociception in a time-dependent manner; and 3) learning and prepulse inhibition impairments. Additionally, most neural activity and behavior changes appear 2 hours after ingestion, suggesting that interventions around this time might be effective in reversing/reducing the effects of AHDECC. SIGNIFICANCE STATEMENT: The effects of high-dose edible cannabis on behavior and neural circuitry are poorly understood. We found that the effects of acute high-dose edible cannabis consumption (AHDECC), which include decreased gamma power, hypothermia, hypolocomotion, analgesia, and learning and information processing impairments, are time and sex dependent. Moreover, these effects begin 2 hours after AHDECC and last for at least 24 hours, suggesting that treatments should target this time window in order to be effective.

Dose Estimation Utility in a Population Pharmacokinetic Analysis of Inhaled Δ9-Tetrahydrocannabinol Cannabis Market Products in Occasional and Daily Users

BACKGROUND

Unusually high variability in blood Δ9-tetrahydrocannabinol (THC) concentrations have been observed in subjects inhaling similar cannabis products over similar time periods when consumption is ad libitum. This makes simple gravimetric dose estimation a poor predictor of THC exposure. Population pharmacokinetic analyses of blood THC concentration versus time data are routinely used to estimate pharmacokinetic parameters. The aim of this study was to estimate the inhaled dose of THC in occasional and daily users of high potency market cannabis.

METHODS

Blood THC concentrations were measured for 135 minutes from 29 participants who either smoked high concentration flower or inhaled concentrates ad libitum during a 15-minute session. Frequent blood samples were obtained over the following 135 minutes.

RESULTS

The estimated central and rapidly equilibrating volumes of distribution of a 3-compartment model were 19.9 ± 1.2 and 51.6 ± 4.7 L whereas the intercompartmental clearances were 1.65 ± 0.14 and 1.75 ± 0.10 L/min, respectively. Covariate-adjusted analysis revealed that the estimated inhaled THC dose was considerably less among occasional users compared with daily users.

CONCLUSIONS

Three-compartment pharmacokinetics of THC did not differ among the 3 user groups, and the early phase (first 135 minutes postinception of inhalation) kinetics were similar to those previously described after smoking low potency cannabis products. Therefore, inhaled THC dose can be estimated from pharmacokinetic data and covariate-driven adjustments can be used to estimate THC doses, based on the participant cannabis usage pattern (occasional versus daily), improving the accuracy of THC exposure estimates compared with those derived from weighed THC content alone.

Edible cannabis for chronic low back pain: associations with pain, mood, and intoxication

Introduction

Cannabis, commonly known for both therapeutic and intoxicating effects, is gaining accessibility on legal markets and traction as a potential alternative therapy for pain mediation, particularly in those suffering from chronic low back pain. However, the effectiveness in this population of legal market forms of cannabis, particularly commonly used edibles, is unknown.

Methods

Therefore, this study utilized a naturalistic prospective design where participants with chronic low back pain with intentions to initiate cannabis use for treatment were recruited and self-selected edible cannabis products containing varying amounts of delta- 9 tetrahydrocannabinol (THC) and cannabidiol (CBD). Products were categorized as CBD-dominant, THC-dominant, or combined THC and CBD (THC + CBD).

Results

249 participants [140 female (56.62%), mean (SD) age of 46.30 (16.02), 90% White] were tracked over 2 weeks of ad libitum use and assessed during a naturalistic acute cannabis administration session on changes in pain, mood, and subjective drug effects. During acute administration, a significant correlation between THC dose and short-term pain relief was found, suggesting that higher THC doses were associated with greater pain reduction (p < .05). In addition, THC was associated with higher levels of subjective cannabis drug effects (p < .001), regardless of whether CBD was also in the edible product. Acute CBD dose was primarily associated with short-term tension relief (p < .05); however, there were no associations between CBD dose and acute pain. Over the 2-week ad libitum administration period results suggested pain reductions across participants using all forms of cannabis. However, trends suggested that more frequent use of CBD-dominant edible cannabis may be associated with greater reductions in perceived pain over the 2-week observation period (p = .07).

Discussion

These findings support the short-term analgesic effects of THC and anxiolytic effects of CBD and further suggest that orally-administered THC and CBD should continue to be evaluated for the potential to provide both acute and extended relief from chronic low back pain.

Clinical Trial Registration

https://clinicaltrials.gov/study/NCT03522324?locStr=Boulder,%20CO&country=United%20States&state=Colorado&city=Boulder&cond=chronic%20low%20back%20pain&intr=Cannabis&rank=1, identifier NCT03522324.

Human laboratory models of reward in substance use disorder

Human laboratory models in substance use disorder provide a key intermediary step between highly controlled and mechanistically informative non-human preclinical methods and clinical trials conducted in human populations. Much like preclinical models, the variety of human laboratory methods provide insights into specific features of substance use disorder rather than modelling the diverse causes and consequences simultaneously in a single model. This narrative review provides a discussion of popular models of reward used in human laboratory research on substance use disorder with a focus on the specific contributions that each model has towards informing clinical outcomes (forward translation) and analogs within preclinical models (backward translation). Four core areas of human laboratory research are discussed: drug self-administration, subjective effects, behavioral economics, and cognitive and executive function. Discussion of common measures and models used, the features of substance use disorder that these methods are purported to evaluate, unique issues for measure validity and application, and translational links to preclinical models and special considerations for studies wishing to evaluate homology across species is provided.

Acute and Extended Anxiolytic Effects of Cannabidiol in Cannabis Flower: A Quasi-Experimental ad libitum Use Study

Objective: Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have varying pharmacological actions with differential effects on acute and extended affective states, incuding anxiety. We aimed to study these effects on anxiety in legal market forms of cannabis. Method: This study makes use of a nonequivalent control group quasiexperimental design. Forty-two participants with anxiety symptions who were not using cannabis were compared to 258 participants with anxiety symptoms who used cannabis flower (∼3-4 times per week). Participants who used cannabis were randomly assigned to one of three legal market cannabis conditions; THC-dominant (24% THC, <1% CBD), THC+CBD (12% THC, 12% CBD), or CBD-dominant (<1% THC, 24% CBD). Changes in anxiety symptoms over 4-weeks were measured by the Patient Global Impression of Change (PGIC) scale and the Depression, Anxiety, and Stress Scale (DASS). Acute changes in subjective mood immediately after cannabis use were measured by the Profile of Mood States (POMS) Elation, Tension, and Paranoia subscales and the Addiction Research Center Inventory intoxication scale. Results: While all participants reported anxiety reductions over the 4-week study on the PGIC (F=30.65, p<0.001) and DASS anxiety measures (F=115.88, p<0.001), ad libitum CBD-dominant cannabis use was associated with lower scores on the DASS anxiety subscale compared to THC-dominant use when accounting for frequency of use (difference=-1.03, SE=0.45, p=0.02). Similarly, acute CBD-dominant cannabis use was associated with lower scores on the POMS tension and paranoia subscales (POMS tension: CBD-dominant vs. THC-dominant: difference=-0.41 SE=0.1, p<0.001; CBD-dominant vs. THC+CBD: difference=-0.28, SE=0.07, p=0.04; POMS paranoia: CBD-dominant vs. THC-dominant: difference=-0.49, SE=0.1, p<0.001; CBD-dominant vs. THC+CBD: difference=-0.33, SE=0.09, p=0.01). Participants in all cannabis conditions experienced acute changes in positive mood and subjective drug effects. Conclusions: This study provides novel information on the impacts of legal market cannabis with varying ratios of THC to CBD in indviduals with anxiety symptoms. Findings suggest that THC did not increase anxiety and that CBD-dominant forms of cannabis were associated with acute tension reduction that may translate to longer-term reductions in anxiety symptoms. Clinical Trial Registration: NCT03491384.

The Reddit cannabis subjective highness rating scale: Applying computational social science to explore psychological and environmental correlates of naturalistic cannabis use

Social media data provide unprecedented access to discussions of active, naturalistic, and often real-time cannabis use in an era of cannabis policy liberalization. The aim of this study was to explore psychological and environmental correlates of cannabis effects by applying computational social science approaches to a large dataset of unprompted reports of naturalistic cannabis use with corresponding self-reported numerical ratings of subjective highness. Post title text was extracted via the Pushshift dataset from N = 328,865 posts to the r/trees Reddit community, where posters self-assess and disclose how high they feel on a scale from 1 to 10 (M = 6.9, SD = 1.8). Structural topic modelling and Linguistic Inquiry and Word Count (LIWC) dictionary-based approaches were applied to identify (1) frequently discussed topics and (2) text indicative of 5 psychological processes (affective, social, cognitive, perceptual, biological), respectively, as well as to examine relationships between subjective highness and (1) topic prevalence and (2) psychological process word counts. A 40-topic model was selected for interpretation based on semantic coherence and exclusivity. The most discussed topics in a 40-topic model were characterized by references to smoking places, social contexts, positive affect, cognitive states, as well as food and media consumed. In LIWC dictionary analyses, words mentioning affective, social, and cognitive processes were referenced more often than perceptual or body processes. Posters reported greater subjective highness when using language that referred to in-person social environments and lower subjective highness when using language that referred to online social environments and positive affect psychological states. This examination of unprompted online reports of naturalistic cannabis use identified textual content referring to affect and to other people as being associated with perceived effects of cannabis. These affective and social aspects of the cannabis use experience were salient to active posters in this online community and should be integrated into experience sampling methods and behavioral pharmacology research, as well as public health messaging.

The impact of cannabinoids on methemoglobin formation and hemoglobin oxygen affinity: An ex-vivo study

The affinity of hemoglobin (Hb) to oxygen (O2) influences processes of oxygen delivery and extraction at the tissue level. Despite cannabinoids being utilized or ingested in various ways, their possible impact on Hb-O2 affinity has barely been studied. This is an experimental ex-vivo trial. Venous blood samples were drawn from 5 male and 6 female healthy volunteers and subsequently exposed to different cannabinoid types: (delta-9-tetrahydrocannabinol [Δ9-THC], delta-8-tetrahydrocannabinol [Δ8-THC], cannabidiol [CBD]) at different concentrations. Oxygen dissociation curves (ODC) were measured and blood gas analyses were performed for methemoglobin (MetHb) determination. The results revealed no MetHb formation. Besides two statistically significant changes (+1.4 mmHg and -0.9 mmHg) in the female cohort, following Δ9-THC and Δ8-THC exposure, no further P50 changes could be observed. The study demonstrated an in-vitro effect of selected cannabinoids and dosages on P50 values in female participants, with variations not observed at other dosages, leaving the underlying mechanisms open for debate. MetHb formation, as potential mechanism, was not detected in this study. The precise reasons why changes only occurred at specific dosages remain unclear, indicating a need for further in-vivo research to understand the interaction between cannabinoids and Hb-O2 affinity completely.

Investigating the Relationship Between Cannabis Expectancies and Anxiety, Depression, and Pain Responses After Acute Flower and Edible Cannabis Use

Objective: Cannabis has been touted for a host of pharmacological and therapeutic effects and users commonly report reduced symptoms of physical and mental health conditions, including anxiety, depression, and chronic pain. While there is existing empirical evidence supporting these effects of cannabis use, little is known about the extent to which these effects result from pharmacological versus expectancy factors. We evaluated the associations between participants' cannabis expectancies and their acute self-reported reactions after using legal market forms of cannabis with varying levels of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) in three domains: anxiety, depression, and pain. Methods: Fifty-five flower and 101 edible cannabis users were randomly assigned and asked to purchase at a local dispensary one of three products containing varying levels of CBD and THC. Participants completed a baseline assessment where they reported expectancies about general health effects of cannabis use and an experimental mobile laboratory assessment where they administered their assigned products. Edible users also reported their domain-specific expectancies about cannabis use in improving anxiety, depression, and pain. Following administration, participants completed acute indicators of anxiety, depression, and pain operationalized through subjective acute tension, elation, and a single-item measure of pain. Results: Among flower users, more positive expectancies for cannabis to improve general health were correlated with greater reductions in tension at acute post-use. This finding was replicated among edible users. Unlike flower users, more positive expectancies for cannabis to improve general health were also correlated with greater increases in elation and greater reductions in pain among edible users. More positive expectancies for cannabis to improve depression and pain were also correlated with greater increases in elation and greater reductions in pain, respectively, among edible users. Conclusions: Cannabis users' expectancies significantly impacted some of the acute subjective effects of legal market cannabis products. Among both flower and edible users, consistent, significant expectancy effects were found. Results were consistent with prior findings and demonstrate the need to measure and control pre-existing expectancies in future research that involves cannabis administration. Clinical trial registration number: NCT03522103.

Typical Hits, Grams, or Joints: Evaluating Cannabis Survey Measurement Strategies for Quantifying Consumption

Aim: Standardized survey measures that capture diverse cannabis consumption patterns are needed to inform public health and policy. Our team is developing a flexible, personalized, low-burden survey item inventory to measure cannabis use patterns and estimate milligrams of THC (mgTHC) consumption in large samples. This study aimed to identify measurement gaps and analysis implications associated with an initial pool of candidate items that assessed use of cannabis flower and concentrate products (smoked and/or vaporized). Methods: Adult cannabis consumers (n=4247) completed an online survey assessing cannabis use frequency, quantity, product types, product potencies (%THC), and methods of administration. Participants chose to report their consumption quantities using one of three units: "hits per day," "grams per week," or "joints per week." Respondents also indicated whether their past 7-day consumption pattern represented their typical pattern. Results: Eighty-one percent had used cannabis daily in the past week. Thirty-two percent, 53%, and 15% chose to report flower and concentrate consumption quantity in hits, grams, and joints, respectively. Approximately 80-90% of responses for the number of hits, grams, and joints consumed were less than the maximum response option-suggesting that response options captured the full range of potential cannabis consumption behaviors. Those who chose grams or joints units were generally more likely to endorse higher risk cannabis use (e.g., morning use, high %THC products) in the past week than those who chose the hits unit (adjusted Odds Ratio range: 1.2-3.9). Among those who reported that the past week represented their typical behavior (83%), past 30-day and past 7-day frequencies were highly correlated (Spearman's Rho=0.77)-supporting the feasibility of using lower burden "typical week" items to extrapolate patterns beyond a 1-week time frame. Conclusion: Results from this online convenience sample of frequent cannabis consumers suggest that the current items yield coherent and expected response patterns. Although additional testing is required, a standardized, flexible survey instrument for large-scale assessment of cannabis patterns and calculation of mgTHC seems within reach.

How much cannabis is used in a joint in Australia? An experimental investigation into use by potency and frequency

INTRODUCTION

Cannabis use is highly prevalent in Australia, yet current survey metrics measure tetrahydrocannabinol (THC) exposure with limited accuracy. Often survey items measure cannabis quantity by assuming specific modes of use (i.e., 'how many joints do you use?'), which fail to capture variations in cannabis use and the diverse modes of use (e.g., joints, cones, spliffs). This study investigated how much cannabis is used in these modes of administration in an Australian sample.

METHODS

Participants (N = 31, Mage  = 25.77; 51% university students) completed the Roll a Joint Paradigm in which they rolled joints, spliffs and packed cones as they would typically, using oregano as 'cannabis.' Participants then prepared each again but with cannabis of higher or lower potency.

RESULTS

The amount of cannabis used across different modes of administration was variable: joints (range 0.10-1.25 g), spliffs (range 0.12-1.21 g) and cones (range 0.03-0.41 g). Participants who used cannabis daily rolled three times the amount of cannabis into a joint.

DISCUSSION AND CONCLUSIONS

The amount of cannabis used in common modes of administration may be highly variable. Daily use may be associated using larger quantities of cannabis. Titration attempts based on potency were not proportional or consistent across modes of administration. The results indicate people may adjust the quantity of cannabis based on perceived potency, however, not proportional to THC concentration. Inconsistency in the amount of cannabis used based on potency and within different modes of administration may represent a problem for self-report metrics which ask participants to report cannabis use in joints.

Thoughtfully Integrating Cannabis Products Into Chronic Pain Treatment

Cannabis products (CPs) and cannabis-based medicines (CBMs) are becoming increasingly available and are commonly used for pain management. The growing societal acceptance of cannabis and liberalization of cannabis laws allows patients to access CPs with minimal clinical oversight. While there is mechanistic plausibility that CPs and CBMs may be useful for pain management, the clinical trial literature is limited and does not refute or support the use of CBMs for pain management. Complicating matters, a large and growing body of observational literature shows that many people use CPs for pain management and in place of other medications. However, products and dosing regimens in existing trials are not generalizable to the current cannabis market, making it difficult to compare and reconcile these 2 bodies of literature. Given this complexity, clinicians need clear, pragmatic guidance on how to appropriately educate and work with patients who are using CBMs for pain management. In this review, we narratively synthesize the evidence to enable a clear view of current landscape and provide pragmatic advice for clinicians to use when working with patients. This advice revolves around 3 principles: (1) maintaining the therapeutic alliance; (2) harm reduction and benefit maximization; and (3) pragmatism, principles of patient-centered care, and use of best clinical judgment in the face of uncertainty. Despite the lack of certainty CPs and chronic pain management use, we believe that following these principles can make most of the clinical opportunity presented by discussions around CPs and also enhance the likelihood of clinical benefit from CPs.

Baseline affective symptomatology moderates acute subjective effects of high potency THC and CBD cannabis concentrates

Highly potent cannabis concentrates are widely available and associated with affective disturbance and cannabis use disorder. Little is known about the effects of concentrated Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) and their relationship to long-term affect. We explored how baseline affective symptoms (anxiety and depression) relate to acute (i.e., immediate or short-term) subjective mood and intoxication effects during naturalistic use of cannabis concentrates. Fifty-four cannabis users (48% female; Mage = 29.87) were assigned to ad libitum use of either a THC-dominant (84.99% THC and THCa, < 1% CBD) or CBD-dominant (74.7% CBD, 4.1% CBDa, 4.5% THC and THCa) concentrate. Individuals were assessed at baseline and before, immediately after, and 1 hr after naturalistic use of their assigned product. Models regressed each outcome on time, product condition, baseline affective symptoms, and their interactions. An interaction emerged between condition and baseline depression symptoms on positive mood (F = 9.47, p < .005); higher depression symptom level was associated with higher positive mood with THC-dominant product use. There was an interaction between condition, baseline depression symptoms, and time on negative mood (F = 5.55, p < .01); negative mood decreased with CBD-dominant product use for all depression symptom levels but increased with THC-dominant product use at high levels. Finally, there was an interaction between condition and time on intoxication (F = 3.72, p = .03); the THC-dominant condition was more intoxicated postuse than the CBD-dominant condition. This novel exploratory study suggests that baseline affect moderates the acute effects of ad libitum use of THC and CBD concentrates such that preexisting affective symptoms modulate the intensity of subjective drug experiences. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Characterization of cannabinoid plasma concentration, maternal health, and cytokine levels in a rat model of prenatal Cannabis smoke exposure

Cannabis sativa has gained popularity as a "natural substance", leading many to falsely assume that it is not harmful. This assumption has been documented amongst pregnant mothers, many of whom consider Cannabis use during pregnancy as benign. The purpose of this study was to validate a Cannabis smoke exposure model in pregnant rats by determining the plasma levels of cannabinoids and associated metabolites in the dams after exposure to either Cannabis smoke or injected cannabinoids. Maternal and fetal cytokine and chemokine profiles were also assessed after exposure. Pregnant Sprague-Dawley rats were treated daily from gestational day 6-20 with either room air, i.p. vehicle, inhaled high-Δ9-tetrahydrocannabinol (THC) (18% THC, 0.1% cannabidiol [CBD]) smoke, inhaled high-CBD (0.7% THC, 13% CBD) smoke, 3 mg/kg i.p. THC, or 10 mg/kg i.p. CBD. Our data reveal that THC and CBD, but not their metabolites, accumulate in maternal plasma after repeated exposures. Injection of THC or CBD was associated with fewer offspring and increased uterine reabsorption events. For cytokines and chemokines, injection of THC or CBD up-regulated several pro-inflammatory cytokines compared to control or high-THC smoke or high-CBD smoke in placental and fetal brain tissue, whereas smoke exposure was generally associated with reduced cytokine and chemokine concentrations in placental and fetal brain tissue compared to controls. These results support existing, but limited, knowledge on how different routes of administration contribute to inconsistent manifestations of cannabinoid-mediated effects on pregnancy. Smoked Cannabis is still the most common means of human consumption, and more preclinical investigation is needed to determine the effects of smoke inhalation on developmental and behavioural trajectories.

The Naturalistic Cannabis Administration Protocol (NCAP): A Proof-of-Concept Study

Lab-based studies examining the effects of cannabis administration on human behavior compromise ecological validity due to the influence of set and setting. Contextual factors of clinical settings have long been recognized as producing measurable changes in physiology, emotionality, and cognition. Among people who use drugs, these settings may be associated with higher levels of perceived stigma and stereotype threat which may meaningfully confound the effects of cannabis on outcomes of interest. Recent liberalization of cannabis regulation may allow novel and more ecologically valid approaches to assessing the acute effects of cannabis. The Naturalistic Cannabis Administration Protocol (NCAP) is a novel paradigm for the study of acute cannabis effects in an ecologically valid manner. Two independent studies demonstrated the safety and feasibility of the NCAP. Participants (N= 79; Mage = 25.44, SD = 5.67) self-administered the cannabis of their choice in their home and then (Study 1; n= 47) engaged in a leisure activity or (Study 2; n= 32) underwent cognitive assessment remotely via videoconference following cannabis administration. The NCAP was well tolerated across samples with no reported adverse events. These findings provide a rationale for the adoption of the NCAP to reduce research barriers and develop our research capabilities to fit the landscape of cannabis use today.

Trends in Illicit Cannabis Potency based on the Analysis of Law Enforcement Seizures in the Southern Area of Rome

Cannabis remains the most illicitly produced and consumed substance worldwide, and the average trans-Δ9-tetrahydrocannabinol (THC) content in cannabis products (marijuana, hashish) has increased over time. This paper presents data about THC concentration in cannabis resin samples seized by law enforcement from 2015 to 2022 in the southern area of Rome (Italy). From 2015 to 2022, more than 1000 hashish samples were analyzed; the average THC content was 18.0% and dramatically increased from 13.7% (2015) to 27.1% (2022). The potency of THC in some samples characterized by unusual shape and color was higher than 24% and, in a few cases, higher than 40%. The age group most involved in seizures of cannabis resin concerned males aged between 15 and 36 years old. The spread of this phenomenon increases the risk of adverse health outcomes. Many observational studies compare the increased cannabis potency with the onset of psychosis, depression, anxiety and cannabis use disorders (CUDs), mainly in young adults. THC-potency monitoring provides data that can be helpful to create a network of communication and interaction between universities, and legislative and public health institutions to support education, awareness and surveillance related to cannabis abuse.

Momentary Craving, Craving Variability, and Cannabis Use: Associations With THC Concentrates and Sex

OBJECTIVE

Ecological momentary assessment (EMA) studies are well positioned to assess the impact of craving on cannabis use in real time and may better capture its time-varying nature. The goal of this exploratory study was to examine whether momentary craving and craving variability predict subsequent use of cannabis and how baseline concentrate use status and male sex might affect these relationships.

METHOD

College students residing in a state with legal recreational cannabis use who used cannabis twice a week or more completed a baseline interview and signal-contingent EMA for 2 weeks using a smartphone application. Hierarchical (multi-level) regression was used to examine time-lagged associations between craving, craving variability, and subsequent cannabis use. Baseline concentrate use and male sex were examined as moderators.

RESULTS

Participants (N = 109) included 59% women, with an average age of 20.2 years, and most using cannabis near-daily or daily. A main effect for craving (within-level effect) on the likelihood of cannabis use at the next EMA instance was found (odds ratio = 1.292, p < .001), although this effect was moderated by concentrate use status. For men, between-level increases in craving led to a greater likelihood of cannabis use at the next instance, but greater craving variability led to a lower likelihood of use. Greater variability in craving was associated with a greater likelihood of cannabis use among those using concentrates.

CONCLUSIONS

The experience of craving may differ based on important participant characteristics. More research examining the fluctuating nature of craving and the role of cannabis potency on craving is warranted.

Cognitive test performance in chronic cannabis flower users, concentrate users, and non-users

Extremely high-potency cannabis concentrates are becoming increasingly available and popular among consumers. While prior research indicates these products are perceived to have greater detrimental effects relative to cannabis flower, few studies have examined their relative objective effects, and no existing studies have compared the cognitive test performance of sober flower users, concentrate users, and non-users. A total of 198 healthy adults (98 non-users, 46 exclusive flower users, and 54 concentrate users) were administered a battery of tests of memory, psychomotor speed, attention, and executive functioning under sober laboratory-controlled conditions. Significant group differences were detected on tests of verbal free recall and episodic prospective memory, with both the flower users and concentrate users demonstrating significantly worse performance than non-users. Concentrate (but not flower) users performed worse than non-users on a measure of source memory, but contrary to our hypothesis, there were no significant differences between flower and concentrate users on any of the cognitive tests. Results indicate that, under sober conditions, individuals who regularly use concentrates are no more cognitively impacted than those who exclusively use flower. These null findings may reflect the tendency for concentrate users to self-titrate and use significantly lower quantities of concentrates than flower.

A Metabolomics and Big Data Approach to Cannabis Authenticity (Authentomics)

With the increasing accessibility of cannabis (Cannabis sativa L., also known as marijuana and hemp), its products are being developed as extracts for both recreational and therapeutic use. This has led to increased scrutiny by regulatory bodies, who aim to understand and regulate the complex chemistry of these products to ensure their safety and efficacy. Regulators use targeted analyses to track the concentration of key bioactive metabolites and potentially harmful contaminants, such as metals and other impurities. However, the metabolic complexity of cannabis metabolic pathways requires a more comprehensive approach. A non-targeted metabolomic analysis of cannabis products is necessary to generate data that can be used to determine their authenticity and efficacy. An authentomics approach, which involves combining the non-targeted analysis of new samples with big data comparisons to authenticated historic datasets, provides a robust method for verifying the quality of cannabis products. To meet International Organization for Standardization (ISO) standards, it is necessary to implement the authentomics platform technology and build an integrated database of cannabis analytical results. This study is the first to review the topic of the authentomics of cannabis and its potential to meet ISO standards.

Adult use of highly-potent Δ9-THC cannabis concentrate products by U.S. state cannabis legalization status, 2021

BACKGROUND

Compared to plant/flower cannabis products, cannabis concentrates have higher average potency of delta-9-tetrahydrocannabinol (Δ9-THC), which may be associated with greater likelihood of cannabis-related harms. Information on factors associated with use of cannabis concentrates is needed.

METHODS

Respondents were 4,328 adult past-7-day cannabis users from all 50 U.S. states and Washington DC (DC) who participated in an online 2021 survey. Using logistic regression to generate adjusted odds ratios (aOR), we investigated whether participants in states that enacted recreational cannabis laws (RCL, 12 states plus DC [treated as a state], n = 1,236) or medical cannabis laws (MCL-only, 23 states, n = 2,030) by December 31, 2020 were more likely than those in states without cannabis laws (no-CL, 15 states, n = 1,062) to use cannabis concentrate products in the prior 7 days.

RESULTS

Most participants (92.4%) used plant material in the prior 7 days; 57.0% used cannabis concentrates. In RCL, MCL and no-CL states, concentrate use was reported by 61.5%, 56.6%, and 52.5%, respectively. Compared to participants in no-CL states, odds of using cannabis concentrate products were greater among those in RCL states (aOR = 1.47; CI = 1.17-1.84) and MCL-only states (aOR = 1.29; CI = 1.08-1.55). Whether states had legally-authorized dispensaries had little effect on results.

CONCLUSION

Results suggest that individuals in MCL-only and RCL states are more likely to use cannabis concentrate products. Determining mechanisms underlying these results, e.g., commercialization, could provide important information for prevention. Clinicians should be alert to patient use of concentrates, especially in MCL-only and RCL states. Continued monitoring is warranted as additional states legalize cannabis use.

Cannabis Involvement and Demand in Frequent Concentrate Users Versus Predominantly Flower Users

OBJECTIVE

Cannabis concentrate products contain more of the intoxicating cannabinoid, tetrahydrocannabinol, than flower products and, thus, may produce greater harm. Indeed, concentrate use is associated with greater cannabis dependence and problems (e.g., anxiety) than flower use. Given this, continued examination of concentrate versus flower use differences on associations with various cannabis measures may be useful. These measures include behavioral economic demand for cannabis (i.e., its subjective reinforcing value), use frequency, and dependence.

METHOD

In the present study of 480 cannabis users, those who were frequent concentrate users (n = 176) were compared with predominantly flower users (n = 304) regarding the relationship of two latent drug demand metrics assessed by the Marijuana Purchase Task to cannabis use frequency (i.e., days of cannabis use) and cannabis dependence (i.e., Marijuana Dependence Scale scores).

RESULTS

Two previously observed latent factors emerged, based on confirmatory factor analysis: amplitude, reflecting maximum consumption, and persistence, reflecting cost insensitivity. Group comparisons showed that amplitude was greater among the concentrate versus flower group, but no difference was found for persistence. Further, using structural path invariance testing, the factors were differentially associated with cannabis use frequency across groups. Amplitude was positively associated with frequency for both groups, whereas persistence was negatively associated with frequency for the flower group. Neither factor was associated with dependence for either group.

CONCLUSIONS

Findings continue to indicate that the demand metrics, although distinct, can be parsimoniously condensed into two factors. In addition, method of administration (i.e., concentrate vs. flower use) may affect how demand for cannabis relates to frequency of use. Associations were notably stronger with frequency relative to dependence.

Edible marijuana and cycle ergometer exercise

Purpose: There is extensive public and scientific interest in the influence of cannabis and the psychoactive cannabinoid, delta-9-tetrahydrocannabinol (THC), on exercise performance. Unfortunately, recent, up-to-date studies are lacking. The aim of the current study was to address the hypothesis that ingestion of edible marijuana, prior to exercise, would have unfavorable effects on the physiological response to exercise and on exercise performance. Methods: 17 Healthy adult male and female habitual exercisers, who were regular users of cannabis products, were screened for study participation. 10 were enrolled, and data from 9 [8 males, 1 female, aged 25±3 years, with peak oxygen uptake of 56.5±11.7 ml/kg/min (mean ± SD)] were retained. Participation included two exercise sessions, each preceded by self-administration and ingestion of either edible marijuana (containing 10 mg THC) or placebo. Cardio-respiratory responses (via indirect calorimetry) to stationary cycle ergometer exercise (8 min at 50, 100 and 150 W) were recorded before completion of a 20-min Functional Threshold Power test (FTP²⁰) and a sprint test involving maximal effort until volitional fatigue. Results: Edible marijuana increased the concentration of circulating THC and THC metabolites, and evoked sensations of intoxication and altered psychoactive state. Cardio-respiratory responses to staged cycle ergometer exercise were normal and were unaffected by edible marijuana. Compared with placebo, edible marijuana did not influence FTP²⁰ (Placebo 253±75 vs THC: 251±72 W (mean±SD); p > 0.45) or peak power output during the sprint test (Placebo: 710±201 vs. THC: 732±136 W; p = 0.864). Conclusion: 10 mg of THC, when ingested prior to exercise by regular exercisers and habitual users of cannabis, had little effect on the physiological response to standardized cycle ergometer exercise, and was neither ergogenic nor ergolytic.

Using ecological momentary assessment and a portable device to quantify standard tetrahydrocannabinol units for cannabis flower smoking

AIMS

To evaluate the feasibility and validity of a new method of quantifying cannabis flower use, integrating the amount of cannabis flower smoked, and the potency of the cannabis flower.

DESIGN

Ecological momentary assessment (EMA) for 14 days.

SETTING

Participants' daily lives in Columbia, Missouri, USA.

PARTICIPANTS

A total of 50 community participants, who were regular cannabis flower smokers (48% female).

MEASUREMENTS

Momentary subjective intoxication ratings following cannabis flower smoking; momentary quantity of cannabis flower smoked; potency of cannabis flower smoked in terms of percentage of tetrahydrocannabinol (THC) concentration assessed with a portable device, the Purpl Pro; and time since finished smoking.

FINDINGS

Participants completed our field testing of their cannabis flower (96.2%) and were compliant with our 2-week EMA protocol (73% for random prompts and 91% for morning reports). Momentary subjective intoxication ratings trended down as a function of time since smoking (r = -0.10, P = 0.004, 95% CI, [-0.17, -0.03]). Multi-level model (MLM) results indicated the momentary standard THC units (mg THC) were positively associated with momentary subjective intoxication ratings (b = 0.01, P = 0.03, 95% CI, [0.01, 0.012]).

CONCLUSIONS

There is evidence to support the feasibility and initial validity of a new method of quantifying cannabis flower use into standard tetrahydrocannabinol units. Researchers investigating the effects of cannabis flower use on a range of outcomes (e.g. neurobehavioral effects, emotional sequelae, and driving impairment) as well as in clinical treatment trials might adopt this method to provide estimates of cannabis flower use.

Chronic health conditions, acute health events, and healthcare utilization among adults over age 50 in Hawai'i who use cannabis: A matched cohort study

BACKGROUND

Research on cannabis-related health outcomes in diverse older adults is limited. The current study utilized a matched cohort study design to compare older adults in Hawai'i with identified cannabis diagnoses and matched controls on chronic health conditions, acute health events, and healthcare utilization from 2016 to 2020.

METHOD

Patients age 50 + were identified using ICD-10 diagnostic codes for cannabis use, abuse, and dependence using electronic health record data from an integrated health system (Kaiser Permanente Hawai'i). Those with cannabis diagnoses (n = 275) were compared to matched non-using controls (n = 275; based on age, sex) on chronic health conditions (coronary heart disease, hypertension, COPD, chronic non-cancer pain), acute health events (myocardial infarction, respiratory symptoms, stroke, persistent or cyclic vomiting, injuries), and healthcare utilization (outpatient, inpatient, and emergency department visits) following case identification for two years.

RESULTS

Participants were 19.3% Native Hawaiian/Pacific Islander, 24.4% Asian, 47.8% White, and 8.5% Other/Unknown, with an average age of 62.8 years (SD=7.3). Adjusting for covariates as possible, participants with a cannabis diagnosis had significantly greater risk of coronary heart disease, chronic non-cancer pain, stroke, myocardial infarction, cyclic vomiting, and injuries, over time, compared to controls. Cannabis use was associated with any and greater frequency of outpatient, inpatient, and emergency department visits.

CONCLUSIONS

In a diverse sample, older adults who used cannabis had worse health conditions and events and used more health services over a two-year period. Future studies should evaluate cannabis-related health outcomes, effects of cannabis problem severity, as well as implications for healthcare in aging populations.

Young adults' familiarity with different cannabis product terms: the need for standardized cannabis surveys

Background

Cannabis legalization has resulted in the proliferation of cannabis products. Participants’ familiarity with terms for these products may have implications for assessment, as unfamiliarity with particular terms may result in under-reports of use.

Methods

A convenience sample of 861 college students from one U.S. university completed a survey in the spring of 2020 about their familiarity with a variety of cannabis product terms and use of a variety of cannabis products.

Results

Participants varied in their familiarity with cannabis product terms. For example, with regard to terms for cannabis concentrates with very high concentrations of THC, 85% of participants reported being familiar with the term “wax pen or THC oil,” but only 27% reported being familiar with the term “butane hash oil (BHO)” (i.e., the oil that composes most concentrates). Moreover, of participants who reported use of concentrates based on selecting pictures of the products they had used (n = 324, 40%), 99% (n = 322) reported having seen a “wax pen or THC oil” based on a written list of product terms, whereas only 20% (n = 65) reported having seen “butane hash oil (BHO).” This suggests that asking about use of “butane hash oil” use may result in lower rates of cannabis concentrate use than asking about use of “wax pen/THC oil.” With regard to terms for marijuana flower, 29% of participants (n = 248) reported being unfamiliar with the term marijuana “buds or flowers.” Of participants who reported use of marijuana flower based on selecting pictures of the products they had used (38% of the sample, n = 329), only 86% (n = 282) reported having seen marijuana “buds or flowers” based on a written list of product terms. This suggests that asking about use of marijuana “buds or flowers” use could result in under-reporting due to lack of familiarity with that term. Finally, when asked to select pictures of the cannabis product(s) that participants thought constituted “marijuana,” participants most commonly selected pictures of marijuana flower (93%), followed by wax pen/THC oil (57%) and edibles (49%).

Conclusions

Young adults vary in their familiarity with cannabis product terms, and some may under-report cannabis use in surveys that rely on written cannabis product terms. Young adults also differ in terms of which cannabis products they think constitute “marijuana.” Although participants’ familiarity with specific cannabis product terms in this sample may not generalize to other populations, results highlight the need for standardized surveys of cannabis use that incorporate pictures of cannabis products to overcome issues related to variability in familiarity with cannabis product terms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00125-0.

Driving Performance and Cannabis Users' Perception of Safety: A Randomized Clinical Trial

IMPORTANCE

Expanding cannabis medicalization and legalization increases the urgency to understand the factors associated with acute driving impairment.

OBJECTIVE

To determine, in a large sample of regular cannabis users, the magnitude and time course of driving impairment produced by smoked cannabis of different Δ9-tetrahydrocannabinol (THC) content, the effects of use history, and concordance between perceived impairment and observed performance.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind, placebo-controlled parallel randomized clinical trial took place from February 2017 to June 2019 at the Center for Medicinal Cannabis Research, University of California San Diego. Cannabis users were recruited for this study, and analysis took place between April 2020 and September 2021.

INTERVENTIONS

Placebo or 5.9% or 13.4% THC cannabis smoked ad libitum.

MAIN OUTCOMES AND MEASURES

The primary end point was the Composite Drive Score (CDS), which comprised key driving simulator variables, assessed prior to smoking and at multiple time points postsmoking. Additional measures included self-perceptions of driving impairment and cannabis use history.

RESULTS

Of 191 cannabis users, 118 (61.8%) were male, the mean (SD) age was 29.9 (8.3) years, and the mean (SD) days of use in the past month was 16.7 (9.8). Participants were randomized to the placebo group (63 [33.0%]), 5.9% THC (66 [34.6%]), and 13.4% THC (62 [32.5%]). Compared with placebo, the THC group significantly declined on the Composite Drive Score at 30 minutes (Cohen d = 0.59 [95% CI, 0.28-0.90]; P < .001) and 1 hour 30 minutes (Cohen d = 0.55 [95% CI, 0.24-0.86]; P < .001), with borderline differences at 3 hours 30 minutes (Cohen d = 0.29 [95% CI, -0.02 to 0.60]; P = .07) and no differences at 4 hours 30 minutes (Cohen d = -0.03 [95% CI, -0.33 to 0.28]; P = .87). The Composite Drive Score did not differ based on THC content (likelihood ratio χ24 = 3.83; P = .43) or use intensity (quantity × frequency) in the past 6 months (likelihood ratio χ24 = 1.41; P = .49), despite postsmoking blood THC concentrations being higher in those with the highest use intensity. Although there was hesitancy to drive immediately postsmoking, increasing numbers (81 [68.6%]) of participants reported readiness to drive at 1 hour 30 minutes despite performance not improving from initial postsmoking levels.

CONCLUSIONS AND RELEVANCE

Smoking cannabis ad libitum by regular users resulted in simulated driving decrements. However, when experienced users control their own intake, driving impairment cannot be inferred based on THC content of the cigarette, behavioral tolerance, or THC blood concentrations. Participants' increasing willingness to drive at 1 hour 30 minutes may indicate a false sense of driving safety. Worse driving performance is evident for several hours postsmoking in many users but appears to resolve by 4 hours 30 minutes in most individuals. Further research is needed on the impact of individual biologic differences, cannabis use history, and administration methods on driving performance.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02849587.

Effects of High-Potency Cannabis on Psychomotor Performance in Frequent Cannabis Users

Background: Recently increased access to cannabis products in the United States has been associated with increased rates of driving after cannabis use. Although numerous studies indicate that cannabis impairs psychomotor and neurocognitive functions that can affect driving ability, the determination of cannabis-impaired driving risk is complicated by the extent to which frequent cannabis users develop tolerance to THC's subjective, cognitive, and psychomotor effects, and by the fact that there is no validated behavioral or biological marker of recent cannabis use or cannabis-related impairment. This study examined the psychomotor impairment-related effects experienced by frequent cannabis users in Colorado after naturalistic consumption of smoked cannabis, both immediately and 1 h postuse. Results were then validated in a smaller replication sample from Washington state. Methods: In the primary Colorado study, participants (n=70) used the DRUID^® mobile app, a brief measure of psychomotor and cognitive domains that are sensitive to the effects of cannabis. First, participants used DRUID to establish a sober baseline impairment score. During a second appointment, they used DRUID at three time points: preuse, immediately after acutely using cannabis, and 1 h postuse. In the Washington replication sample, participants (n=39) used DRUID before acute cannabis consumption and then every half hour for 2.5 h. Results: In both studies, peak DRUID impairment effects were seen immediately after cannabis use, with recovery of performance at 1 h postuse. Specifically, significant quadratic effects of time emerged for both studies (Colorado study: (β=-0.935, SE=0.204, p<0.001); Washington study: β=3.0299, SE=1.3085, p<0.01). Domain-specific effects were tested in the larger Colorado study and were observed for reaction time within a complex divided attention task and a postural-stability balance task. Conclusions: These findings demonstrate that psychomotor impairment emerges immediately after acute cannabis use even in regular users, but decreases significantly 1 h postuse. These results underscore the potential utility of the DRUID app for assessing acute cannabis-related psychomotor impairment. Further research is needed to explore whether the DRUID app and/or the specific psychomotor functions it assesses might serve as a tool for measuring cannabis-related driving impairment. Clinical trials registration number for the Colorado Study: NCT03522103.

Higher risk, higher reward? Self‐reported effects of real‐world cannabis use in Parkinson's disease

Background

Objective

Methods

Results

Conclusions

Effects of cannabidiol in cannabis flower: Implications for harm reduction

Using a federally compatible, naturalistic at-home administration procedure, the present study examined the acute effects of three cannabis flower chemovars with different tetrahydrocannabinol (THC) to cannabidiol (CBD) ratios, in order to test whether chemovars with a higher CBD content produce different effects. Participants were randomly assigned to ad libitum administration of one of three chemovars (THC-dominant: 24% THC, 1% CBD; THC+CBD: 9% THC, 10% CBD; CBD-dominant: 1% THC, 23% CBD); 159 regular cannabis users (male = 94, female = 65) were assessed in a mobile pharmacology lab before, immediately after, and 1 h after ad libitum administration of their assigned chemovar. Plasma cannabinoids as well as positive (e.g., high, elation) and negative (e.g., paranoia and anxiety) subjective effects were assessed at each time points. Participants who used the CBD-dominant and THC + CBD chemovars had significantly less THC and more CBD in plasma samples compared to participants who used the THC-dominant chemovar. Further, the THC + CBD chemovar was associated with similar levels of positive subjective effects, but significantly less paranoia and anxiety, as compared to the THC-dominant chemovar. This is one of the first studies to examine the differential effects of various THC to CBD ratios using chemovars that are widely available in state-regulated markets. Individuals using a THC + CBD chemovar had significantly lower plasma THC concentrations and reported less paranoia and anxiety while also reporting similar positive mood effects as compared to individuals using THC only, which is intriguing from a harm reduction perspective. Further research is needed to clarify the harm reduction potential of CBD in cannabis products.

Pharmacokinetics and central accumulation of delta-9-tetrahydrocannabinol (THC) and its bioactive metabolites are influenced by route of administration and sex in rats

Up to a third of North Americans report using cannabis in the prior month, most commonly through inhalation. Animal models that reflect human consumption are critical to study the impact of cannabis on brain and behaviour. Most animal studies to date utilize injection of delta-9-tetrahydrocannabinol (THC; primary psychoactive component of cannabis). THC injections produce markedly different physiological and behavioural effects than inhalation, likely due to distinctive pharmacokinetics. The current study directly examined if administration route (injection versus inhalation) alters metabolism and central accumulation of THC and metabolites over time. Adult male and female Sprague–Dawley rats received either an intraperitoneal injection or a 15-min session of inhaled exposure to THC. Blood and brains were collected at 15, 30, 60, 90 and 240-min post-exposure for analysis of THC and metabolites. Despite achieving comparable peak blood THC concentrations in both groups, our results indicate higher initial brain THC concentration following inhalation, whereas injection resulted in dramatically higher 11-OH-THC concentration, a potent THC metabolite, in blood and brain that increased over time. Our results provide evidence of different pharmacokinetic profiles following inhalation versus injection. Accordingly, administration route should be considered during data interpretation, and translational animal work should strongly consider using inhalation models.

Acute objective and subjective intoxication effects of legal-market high potency THC-dominant versus CBD-dominant cannabis concentrates

As the market for cannabis concentrate products grows, the lack of research regarding the effects of concentrated THC and CBD becomes more glaring. The present study analyzes cannabinoid blood levels and subjective outcomes of physical sensation and affective state after ad libitum use of legal-market concentrate products. Recreational cannabis users were randomly assigned to THC- or CBD-dominant concentrate products, completing a baseline session, and an experimental mobile laboratory session consisting of timepoints before, immediately after, and one-hour after concentrate use. THC-dominant concentrates induced higher intoxication, and higher ratings of drug effect and drug liking than the CBD-dominant concentrate. Both products induced immediate feelings of elation, diminishing over the subsequent hour. Subjective outcomes in the CBD-dominant group revealed immediate decreases in tension and anxiety relative to pre-use, while the THC-dominant group only saw significant decreases in anxiety after one hour. Paranoia spiked immediately post-use in THC-dominant concentrate users, returning to baseline within an hour. Overall, the CBD-dominant concentrate invoked positive mood effects, lower intoxication and an absence of undesirable effects experienced with the THC-dominant concentrate, potentially mitigating negative effects when combined. Results support the need for further investigation into harm-reduction potential of concentrated CBD when used alone and with THC.

Associations between self-reported cannabis use frequency, potency, and cannabis/health metrics

BACKGROUND

Research shows that cannabis use frequency is associated with cannabis dependence and health metrics. However, much less is known about how self-reported cannabis potency (THC and CBD) may be associated with the same metrics, and whether any associations exist after accounting for frequency of cannabis use. Moreover, even less is known about how these relations may differ across cannabis product forms. This exploratory study examined 1) associations between cannabis frequency, potency, and cannabis/health metrics, and 2) whether associations between potency and cannabis/health metrics remained after controlling for frequency of use.

METHODS

Using a sample of adult recreational cannabis users in Colorado (N = 300), we tested the relationship between self-reported cannabis use metrics of frequency and potency of flower, edible, and concentrate products with separate measures of problematic cannabis use (i.e., dependence, withdrawal, craving), depression, anxiety, and general perceived health.

RESULTS

Greater frequency of flower and concentrate (but not edible) use were associated with greater problematic cannabis use, and greater concentrate use frequency was also associated with more mental health problems. Partial correlations controlling for average frequency of use across all product forms and CBD potency per product showed that one significant association between THC potency and cannabis/health metrics remained (i.e., higher THC concentrate potency with better health), and one emerged (i.e., higher THC concentrate potency with lower cannabis withdrawal).

CONCLUSIONS

Frequency of use is reliably associated with problematic cannabis use for flower and concentrates, but it did not account for all observed associations in this study. Differences in patterns of associations between frequency and potency and cannabis/health metrics across cannabis forms suggest a need for better understanding user reports of THC and CBD potency, individual differences among users, and improved measurement.

Safety and Tolerability of Natural and Synthetic Cannabinoids in Older Adults: A Systematic Review and Meta-Analysis of Open-Label Trials and Observational Studies

BACKGROUND AND OBJECTIVE

Although cannabinoid-based medications are increasingly used by older adults, their safety and tolerability in this age group remain unclear. The purpose of this systematic review was to examine the safety and tolerability of cannabinoid-based medications by conducting a meta-analysis of open-label observational studies of cannabinoid-based medications for all indications in individuals with a mean age of ≥50 years.

METHODS

A systematic search was conducted on PubMed, PsycINFO, MEDLINE, EMBASE and CINHAL. Study quality was assessed using an adapted version of the Grading of Recommendations Assessment, Development and Evaluation criteria and Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. We included studies that (a) were published from 1990 onwards; (b) included older adults (mean age ≥50 years); and (c) provided data on the safety and tolerability of medical cannabinoids. Data were pooled using a random-effects approach. Risk of adverse events, serious adverse events and withdrawals was computed as the incidence rate (IR). Separate analyses were conducted by the cannabinoid-based medication used, for delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD) and a combination of THC and CBD (THC:CBD).

RESULTS

Thirty-eight studies were identified (THC = 23; CBD = 6; THC:CBD = 9; N = 2341, mean age: 63.19 ± 8.08 years, men: 53.86%). THC had a very low incidence of all-cause and treatment-related adverse events (IR: 122.18, 95% confidence interval [CI] 38.23-253.56; IR: 84.76, 95% CI 0.13-326.01, respectively) and negligible serious adverse events (IR = 0). Similar IRs for CBD (all cause, IR: 111.91, 95% CI 1.24-495.93; treatment related, IR: 1.76, 95% CI 4.63-23.05) and no serious adverse events (IR = 0). CBD was not associated with a risk of treatment-related withdrawals. THC had a low risk of all-cause and treatment-related withdrawals (IR: 25.18, 95% CI 12.35-42.52; IR: 7.83, 95% CI 3.26-14.38, respectively). The THC:CBD treatment had a low risk of all-cause and treatment-related adverse events (IR: 100.72, 95% CI 0.25-383.00; IR: 55.38, 95% CI 8.61-142.80, respectively), but reported a risk of all-cause and treatment-related serious adverse events (IR: 21.32, 95% CI 0.18-93.26; IR: 3.71, 95% CI 0.21-11.56, respectively), and all-cause and treatment-related withdrawals (IR: 78.63, 95% CI 17.43-183.90; IR: 34.31, 95% CI 6.09-85.52, respectively). Significant heterogeneity (I² >55%) was present in most analyses.

CONCLUSIONS

Although cannabinoid-based medications were generally safe and acceptable to adults aged over 50 years, these estimates are limited by the lack of a control condition and considerable heterogeneity. Nevertheless, they complement and are consistent with comparable evidence from randomised controlled trials.

Advancing the science on cannabis concentrates and behavioural health

ISSUES

The Cannabis sativa L. plant contains hundreds of phytocannabinoids, but putatively of highest importance to public health risk is the psychoactive cannabinoid delta-9-tetrahydrocannabinol (THC), which is associated with risk for cannabis use disorder, affective disturbance, cognitive harm and psychomotor impairment. Recently, there has been an increase in the use and availability of concentrated cannabis products (or 'concentrates') that are made by extracting cannabinoids from the plant to form a product with THC concentrations as high as 90-95%. These products are increasingly popular nationwide. The literature on these widely available high potency concentrates is limited and there are many unknowns about their potential harms.

APPROACH

This review covers the state of the research on cannabis concentrates and behavioural health-related outcomes and makes recommendations for advancing the science with studies focused on accurately testing the risks in relation to critical public and behavioural health questions.

KEY FINDINGS

Data point to unique behavioural health implications of concentrate use. However, causal, controlled and representative research on the effects of cannabis concentrates is currently limited.

IMPLICATIONS

Future research is needed to explore chronic, acute and developmental effects of concentrates, as well as effects on pulmonary function. We also highlight the need to explore these relationships in diverse populations.

CONCLUSION

While the literature hints at the potential for these highly potent products to increase cannabis-related behavioural health harms, it is important to carefully design studies that more comprehensively evaluate the impact of concentrates on THC exposure and short- and long-term effects across user groups.

Pharmacokinetic Investigation of Commercially Available Edible Marijuana Products in Humans: Potential Influence of Body Composition and Influence on Glucose Control

The purpose of the study was to describe and compare the pharmacokinetics of five commercial edible marijuana products, determine the influence of body composition on pharmacokinetics, and, in light of epidemiology suggesting marijuana may offer diabetes protection, explore the influence of edible marijuana on glucose tolerance. Seven regular users of marijuana self-administered five edible products in a randomized crossover design; each product contained 10 mg of delta-9-tetrahydrocannabinol (THC). Thirty minutes following marijuana ingestion, participants imbibed a 75 g glucose beverage. Time-to-peak plasma THC concentration ranged between 35 and 90 min; maximal plasma THC concentration (C_max) ranged between 3.2 and 5.5 ng/mL. Differences between products in plasma THC concentration during the first 20–30 min were detected (p = 0.019). Relations were identified between body composition and pharmacokinetic parameters for some products; however, none of these body composition characteristics were consistently related to pharmacokinetics across all five of the products. Edible marijuana had no effect on oral glucose tolerance compared with a marijuana-free control (Matsuda Index; p > 0.395). Commercially available edible marijuana products evoke different plasma THC concentrations shortly after ingestion, but do not appear to influence acute glucose regulation. These data may allow recreational marijuana users to make informed decisions pertaining to rates of edible marijuana ingestion and avoid overdose.

Using Population Pharmacokinetic Modeling to Estimate Exposure to Δ9-Tetrahydrocannabinol in an Observational Study of Cannabis Smokers in Colorado

BACKGROUND

Self-report questionnaires, weighing products consumed, and Δ9-tetrahydrocannabinol (THC) biomarkers are established techniques for estimating cannabis exposure. Population pharmacokinetic modeling of plasma THC and metabolite concentrations by incorporating self-reported and weighed products as covariates could improve estimates of THC exposure in regular cannabis users.

METHODS

In this naturalistic study, blood samples were obtained from 36 regular smokers of cannabis for analysis of THC and its 2 metabolites at 4 time points: recruitment and during an experimental mobile laboratory assessment that included 3 time points: before, immediately after, and 1 hour after ad libitum legal market flower use. These data were analyzed using an established model of population pharmacokinetics developed from laboratory-controlled cannabis administration data. Elimination and metabolite production clearances were estimated for each subject as well as their daily THC doses and the dose consumed during the ad libitum event.

RESULTS

A statistically significant correlation existed between the daily THC dose estimated by self-report questionnaire and population pharmacokinetic modeling (correlation coefficient = 0.79, P < 0.05) between the weighed cannabis smoked ad libitum and that estimated by population pharmacokinetic modeling (correlation coefficient = 0.71, P < 0.05).

CONCLUSION

Inclusion of self-reported questionnaire data of THC consumption improved pharmacokinetic model-derived estimates based on measured THC and metabolite concentrations. In addition, the pharmacokinetic-derived dose estimates for the ad libitum smoking event underestimated the THC consumption compared with the weighed amount smoked. Thus, the subjects in this study, who smoked ad libitum and used cannabis products with high concentrations of THC, were less efficient (lower bioavailability) compared with computer-paced smokers of low potency, NIDA cannabis in a laboratory setting.

Acute effects of high-potency cannabis flower and cannabis concentrates on everyday life memory and decision making

Statewide legislation has increased public access to high-potency cannabis flower and concentrates, yet federal restrictions limit researchers’ access to relatively low-potency whole-plant cannabis. The goal of this study was to examine the acute effects of high-potency cannabis on cognition using a novel methodology. We further sought to compare cognitive effects of high-potency cannabis flower with and without cannabidiol (CBD), as well as cannabis concentrates to cannabis flower. 80 cannabis users were randomly assigned to stay sober or use their funds to purchase one of three high-potency cannabis products: (1) high-potency flower (≥ 20% THC) without CBD, (2) high-potency flower with CBD, (3) high-potency concentrates (≥ 60% THC) with CBD. Participants were observed over Zoom videoconferencing while inhaling their product or remaining sober and then were administered tests of everyday life memory (prospective, source, temporal order, and false memory) and decision making (risky choice framing, consistency in risk perception, resistance to sunk cost, and over/under confidence) over Zoom. High-potency cannabis flower with CBD impaired free recall, high-potency flower without CBD and concentrates had detrimental effects on source memory, and all three products increased susceptibility to false memories. CBD did not offset impairments and concentrates were self-titrated producing comparable intoxication and impairment as flower.

Blood and Oral Fluid Cannabinoid Profiles of Frequent and Occasional Cannabis Smokers

Increased prevalence of cannabis consumption and impaired driving are a growing public safety concern. Some states adopted per se driving laws, making it illegal to drive with more than a specified ∆9-tetrahydrocannabinol (THC) blood concentration of THC in a biological fluid (typically blood). Blood THC concentrations decrease significantly (~90%) with delays in specimen collection, suggesting use of alternative matrices, such as oral fluid (OF). We characterized 10 cannabinoids' concentrations, including THC metabolites, in blood and OF from 191 frequent and occasional users by LC-MS-MS for up to 6 h after ad libitum smoking. Subjects self-titrated when smoking placebo, 5.9 or 13.4% THC cannabis. Higher maximum blood THC concentrations (Cmax) were observed in individuals who received the 5.9% THC versus the 13.4% THC plant material. In blood, the Cmax of multiple analytes, including THC and its metabolites, were increased in frequent compared to occasional users, whereas there were no significant differences in OF Cmax. Blood THC remained detectable (≥5 ng/mL) at the final sample collection for 14% of individuals who smoked either the 5.9% or 13.4% THC cigarette, whereas 54% had detectable THC in OF when applying the same cutoff. Occasional and frequent cannabis users' profiles were compared, THC was detectable for significantly longer in blood and OF from frequent users. Detection rates between frequent and occasional users at multiple per se cutoffs showed larger differences in blood versus OF. Understanding cannabinoid profiles of frequent and occasional users and the subsequent impact on detectability with current drug per se driving limits is important to support forensic interpretations and the development of scientifically supported driving under the influence of cannabis laws.

The why behind the high: determinants of neurocognition during acute cannabis exposure

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis.

Analysis of 14 endocannabinoids and endocannabinoid congeners in human plasma using column switching high-performance atmospheric pressure chemical ionization liquid chromatography-mass spectrometry

The endocannabinoid system (ECS) is a complex cell-signaling system. To address the growing need of analytics capturing endocannabinoid levels to investigate the ECS, we developed and validated an assay for the quantitative analysis of 14 endocannabinoids and congeners. A simple extraction using protein precipitation with acetonitrile followed by online-trapping high-performance liquid chromatography-tandem mass spectrometry (LC/LC-MS/MS) was used to monitor the levels of 14 endocannabinoids in plasma. The assay was validated and intra-run and inter-run accuracies and imprecisions as well as matrix effects, recoveries, and sample stabilities were determined. As a proof of concept, a subset of study samples after naturalistic administration of Cannabis flower and concentrate was analyzed. With the exception of N-oleoyl dopamine and oleamide, all endocannabinoids fulfilled the predefined acceptance criteria. Reproducible recoveries and no significant matrix effects were observed. Sample stability was an issue. Analysis of the proof-of-concept study samples revealed a significantly (p = 0.006) higher concentration of docosatetraenoyl ethanolamide in concentrate users (300 ± 13 pg/mL) compared to flower users (252 ± 11 pg/mL). A robust, sensitive high-throughput assay for the quantitation of 14 endocannabinoids and congeners was successfully validated. Our study showed that it is mandatory to (A) appropriately stabilize samples and (B) separate and separately quantify 1-AG and 2-AG; otherwise, study results are unreliable. The analysis of study samples from Cannabis flower users versus Cannabis concentrate users revealed higher levels of docosatetraenoyl ethanolamide and anandamide (n.s.) in high THC concentrate users in accordance with the existing literature, supporting the validity of the assay measurements. Graphical abstract.

Human Laboratory Models of Cannabis Use: Applications for Clinical and Translational Psychiatry Research

Cannabis is increasingly used by individuals with mental health diagnoses and often purported to treat anxiety and various other psychiatric symptoms. Yet support for using cannabis as a psychiatric treatment is currently limited by a lack of evidence from rigorous placebo-controlled studies. While regulatory hurdles and other barriers make clinical trials of cannabis challenging to conduct, addiction researchers have decades of experience studying cannabis use in human laboratory models. These include methods to control cannabis administration, to delineate clinical and mechanistic aspects of cannabis use, and to evaluate potential treatment applications for cannabis and its constituents. In this paper, we review these human laboratory procedures and describe how each can be applied to study cannabis use in patients with psychiatric disorders. Because anxiety disorders are among the most common psychiatric illnesses affecting American adults, and anxiety relief is also the most commonly-reported reason for medicinal cannabis use, we focus particularly on applying human laboratory models to study cannabis effects in individuals with anxiety and related disorders. Finally, we discuss how these methods can be integrated to study cannabis effects in other psychiatric conditions and guide future research in this area.

Cannabis use is not associated with increased balance disturbances in HIV-infected individuals

BACKGROUND

The association between long-term cannabis use and balance disturbances has not been investigated in people living with HIV (PWH). We hypothesized that long-term cannabis use in PWH might be associated with more deleterious effects on balance than in HIV seronegative individuals due to potential neurotoxic interactions between HIV and cannabis.

METHODS

Three thousand six-hundred and forty-eight participants with and without HIV completed an interviewer-administered timeline follow-back assessment to assess lifetime days and quantity of cannabis use and other cannabis use characteristics. A structured clinical interview was used to collect any history of balance disturbance. Comparisons between HIV+ vs the HIV- groups and moderate-severe vs. no or minimal imbalance in participant characteristics (demographics, cannabis use, medication currently used, and neurological disease) were performed using Student t tests for continuous variables and Fisher's exact test for binary and categorical variables. Multivariate logistic regression was applied to determine the interaction effect of total quantity of cannabis use with HIV status on balance disturbance. Age, gender, cDSPN symptoms, gait ataxia, opioid medications, and sedatives were included as covariates in the adjusted model after variable selection. The effect sizes are presented as Cohen's d or odds ratios.

RESULTS

On average, participants were 45.4 years old (SD = 11 years), primarily male (77.7%), and non-Hispanic white (48.1%). A majority of participants were HIV+ (79.1%). Four hundred thirty (11.9%) of the participants reported balance disturbances within the past 10 years. PWH were more likely to have balance disturbances than demographically matched HIV-uninfected participants (odds ratio [OR] 2.66, 95% CI 1.91-3.7). Participants with moderate-severe balance disturbances did not differ from those with no or minimal imbalance in the proportion who had ever used cannabis (73.8% vs. 74.4%; p = 0.8) (OR 1.03, 95% CI 0.80-1.32) neither did they have a higher total amount of cannabis use (4871 vs. 4648; p = 0.3) (Cohen's d 0.11, 95% CI 0.01-0.14). In the HIV- population, those with balance disturbances reported more total amount of cannabis use as compared to those with normal balance (11316 vs 4154; p = 0.007). In the HIV+ population on the other hand, there was no significant association (4379 vs 4773; p = 0.6).

CONCLUSIONS

We found unexpectedly that while long-term cannabis use in HIV- individuals was associated with more severe balance disturbances, there were no associations in HIV+ individuals. This suggests that cannabis use in HIV is safe with respect to balance disturbances. Given that HIV is related to persistent inflammation despite virologic suppression on antiretroviral therapy, future mechanistic studies are needed to determine whether HIV-associated inflammation contributes to the higher prevalence of balance disturbance in HIV+ individuals and whether cannabinoids have anti-inflammatory effects that mitigate HIV-associated balance disturbance.

Do Cannabis Users Reduce Their THC Dosages When Using More Potent Cannabis Products? A Review

Background: Higher potency cannabis products are associated with higher risks of negative physical and psychological outcomes. The US cannabis industry has opposed any restrictions on THC levels, arguing that people titrate their THC doses when consuming higher potency products. Objective: To review research on the degree to which people who use cannabis for recreational purposes can and do titrate their THC doses. Method: A systematic search was conducted for studies published from 1973 to 2020. We included (1) experimental laboratory studies on dose titration of cannabis products that varied in THC content; (2) observational studies on the use of more potent products; and (3) surveys on whether cannabis users titrate when using more potent products. Results: In some experiments, there were inverse associations between the THC content and the amount smoked and smoking topography, while others indicated higher doses consumed and psychological and physiological effects observed. Findings of observational studies of regular cannabis users were more equivocal. In some surveys, cannabis users reported that they use less when using more potent products, but in other surveys, persons who used more potent cannabis had more adverse effects of use. Discussion: There is some evidence from experimental studies that people who use higher potency cannabis for recreational purposes can titrate their THC doses, but less evidence that regular cannabis users do in fact do so. We need much better experimental and epidemiological research to inform the design of regulatory policies to minimize harms from the use of high THC cannabis products.

Does the Combination Matter? Examining the Influence of Alcohol and Cannabis Product Combinations on Simultaneous Use and Consequences in Daily Life

BACKGROUND

Alcohol and marijuana/cannabis are frequently used simultaneously (i.e., SAM use). SAM use is complex, and the ways in which alcohol and cannabis are simultaneously used may reveal differential effects. The purpose of this study was to examine day-level effects of distinct alcohol and cannabis product combinations on simultaneous use and consequences on that day.

METHODS

College student SAM users (N = 274; 50% women; Mage  = 19.82 years) were recruited to complete 54 days of data collection, including 5 repeated daily surveys each day. We identified 12 distinct product combinations reported during SAM-use days. We tested 4 reference groups, with one reflecting the most common use pattern and 3 potentially risky use patterns. We considered 3 outcomes (negative consequences, number of drinks, and number of cannabis uses) and used generalized linear mixed-effects models disentangling within- from between-person effects in all analyses.

RESULTS

Using multiple products (≥2) of alcohol was consistently linked to higher odds of experiencing a negative consequence. Combining beer with only one cannabis product (leaf or concentrate) was consistently associated with lower odds of a consequence. Combining cannabis with multiple alcohol products was associated with heavier alcohol consumption. Using dual cannabis products also was associated with heavier cannabis consumption, but this pattern was not significantly different than using concentrate only on a given day.

CONCLUSION

This is the first study to examine day-level influences of distinct alcohol and cannabis product combinations on consumption and consequences among young adult SAM users. Findings suggest that mixing alcohol products confers greater risk for negative consequences and heavier consumption, whereas there is little difference in cannabis consumption when using concentrate only vs. 2 cannabis products on a given day, except for concentrate + beer. Our findings support existing protective strategies of not mixing alcohol products and avoiding use of cannabis concentrate for SAM use as well.

A within-person comparison of the subjective effects of higher vs. lower-potency cannabis

BACKGROUND

Cannabis concentrates have much higher concentrations of THC than marijuana (flower) and are quickly gaining popularity in the United States. One hypothesis is that use of higher-THC cannabis (concentrates) might result in greater intoxication and more severe acute negative effects than lower-THC cannabis (marijuana), but few studies have compared the subjective effects of concentrates and marijuana.

METHODS

Current (past-year) cannabis users were recruited online to complete a survey about their cannabis use. Cannabis users who reported using both marijuana and concentrates (n = 574) answered questions about the subjective effects of marijuana and, subsequently, the subjective effects of concentrates. Subjective effects were obtained for the following domains: affect, cognitive function, psychotic-like experiences, physiological effects, and reduced consciousness.

RESULTS

Participants reported using marijuana between 5-6 times per week and concentrates slightly more than once per month. Within-person comparisons of the subjective effects of marijuana and concentrates showed that marijuana was rated as producing greater overall positive effects (Marijuana: M = 5.6, Concentrates: M = 4.5; Cohen's d = 0.75, paired t(561) = 14.67, p < .001), including greater positive affect and enhanced cognitive function. Negative effects of both marijuana and concentrates were minimal. Marijuana was selected over concentrates as the 'preferred type' of cannabis by 77.5 % of participants.

CONCLUSIONS

The main difference in the subjective effects of marijuana and concentrates is in terms of their positive effects, with marijuana producing greater positive effects than concentrates. Negative effects of marijuana and concentrates were small, suggesting that extreme negative effects are unlikely for regular cannabis users.