Cannabis-induced psychosis associated with high potency "wax dabs"

The impact of recreational cannabis legalization on youth: the Colorado experience

Over the past two decades, cannabis policies have liberalized in the United States, culminating in the legalization of recreational cannabis in Colorado and Washington state in 2012. This review will focus on the impact of recreational cannabis legalization in Colorado. While the prevalence of past-year and past-month cannabis use has remained relatively steady among adolescents post-legalization, the prevalence of young adult use has continued to rise. Cannabis products with increased potency have become more prevalent and widely used. There are concerns that the use of products with increased potency will increase risk for cannabis use and comorbid mental health disorders, particularly cannabis-induced psychosis and suicidal behavior, although more research is needed to fully understand the impact of high-potency products. Since the legalization of recreational cannabis, numerous additional public health concerns have emerged: unintentional overdoses requiring acute care visits, electronic vaping-associated lung injury, increased motor vehicle collisions related to cannabis consumption, and higher rates of cannabis use during pregnancy. Lessons learned from the first decade of cannabis legalization emphasize the need for research efforts to provide evidence-based guidelines, inform prevention strategies, and implement selective interventions for at-risk populations including youth, individuals with comorbid mental health disorders, and individuals who are pregnant.

Recurrent cannabis-induced catatonia: a case report and comprehensive systematic literature review

Background

Catatonia presents itself as a complex neuropsychiatric syndrome, giving rise to various motor, speech, and behavioral challenges. It is noteworthy that approximately 10% of psychiatric hospital admissions can be attributed to this condition. It is imperative to note that cannabis-induced catatonia, while infrequent, has been linked to the use of marijuana. This connection has the potential to disrupt neurotransmitter systems, necessitating further research for a comprehensive understanding and effective treatment, particularly given the evolving trends in cannabis use. In this context, we shall delve into a unique case of recurrent cannabis-induced catatonia.

Case presentation

A 23-year-old gentleman, who has previously struggled with substance use disorder, experienced the emergence of mutism, social isolation, and a fixed gaze subsequent to his use of cannabis. Remarkably, despite the absence of hallucinations, he exhibited recurrent episodes of catatonia. These episodes were effectively addressed through a combination of electroconvulsive therapy (ECT) and lorazepam administration. Notably, when the lorazepam dosage was gradually reduced to below 2 mg per day, the catatonic symptoms resurfaced; however, they promptly abated upon reinstating the medication. The diagnosis of cannabis-induced catatonia was established, and its management primarily involved a therapeutic approach encompassing ECT and lorazepam. It is pertinent to underscore that this catatonic condition can be directly linked to the individual's cannabis usage.

Conclusion

The connection between cannabis and catatonia is intricate and not entirely comprehended. Although cannabis possesses therapeutic advantages, it can paradoxically trigger catatonia in certain individuals. Multiple factors, such as genetics, cannabinoids, and neurotransmitter systems, contribute to this intricacy, underscoring the necessity for additional research.

THC and CBD: Similarities and differences between siblings

Δ9-tetrahydrocannabinol (THC) and its sibling, cannabidiol (CBD), are produced by the same Cannabis plant and have similar chemical structures but differ dramatically in their mechanisms of action and effects on brain functions. Both THC and CBD exhibit promising therapeutic properties; however, impairments and increased incidence of mental health diseases are associated with acute and chronic THC use, respectively, and significant side effects are associated with chronic use of high-dose CBD. This review covers recent molecular and preclinical discoveries concerning the distinct mechanisms of action and bioactivities of THC and CBD and their impact on human behavior and diseases. These discoveries provide a foundation for the development of cannabinoid-based therapeutics for multiple devastating diseases and to assure their safe use in the growing legal market of Cannabis-based products.

Nationally Representative Surveys on Cannabis Use Lack Product Details Relevant to Public Health

Objectives

Many annual, nationally representative US surveys that assess cannabis use do not collect information on product characteristics despite varying health risks and benefits. Capitalizing on a rich dataset of primarily medical users, the purpose of this study was to describe the degree of potential misclassification in clinically relevant cannabis use measures when primary mode of use is recorded but not product type.

Methods

Analyses consider user-level data from the Releaf App™ database on product types, consumption modes, and potencies in a non-nationally representative sample of 26,322 cannabis administration sessions occurring in 2018, across 3,258 users. Proportions, means, and 95% confidence intervals were calculated and compared across products and modes.

Results

Primary consumption modes were smoking (47.1%), vaping (36.5%), and eating/drinking (10.4%), with 22.7% of users reporting multiple modes of use. Moreover, mode of use did not signify a single product type: users reported vaping both flower (41.3%) and concentrates (68.7%). Of those who smoked cannabis, 8.1% reported smoking concentrates. Concentrates averaged 3.4 times higher tetrahydrocannabinol (THC) potency and 3.1 times higher cannabidiol (CBD) potency than flower.

Conclusions

Cannabis consumers employ multiple consumption modes, and product type cannot be inferred from mode of use. With THC potencies markedly higher in concentrates, these findings underscore the importance of including information on cannabis product types and mode of use in surveillance surveys. Clinicians and policymakers need these data to inform treatment decisions and assess cannabis policies' implications for population health.

Conditional release and cannabis use: Concerns and challenges for community reintegration

This article, which serves as a perspective review, delves into the complexities of cannabis use among individuals preparing for or already on conditional release (CR). These complexities include an association between cannabis use and mental illness and dealing with the fact that the use of illicit substances, such as cannabis, is against CR rules, leading to potential revocation. A focus of this article is the deleterious effects cannabis and synthetic derivatives of cannabis can have for individuals on CR. The article concludes with six-specific recommendations for managing cannabis use in this population with a focus on careful and detailed risk assessments that considers the relationship between substance use and dangerousness, the role of protective factors, the need for a detailed conditional release plan, inpatient and community-based interventions aimed at increasing individual autonomy, and education on the dangers of cannabis use for both the treatment team and the insanity acquittee.

The chemistry and toxicology of vaping

Vaping is the process of inhaling and exhaling an aerosol produced by an e-cigarette, vape pen, or personal aerosolizer. When the device contains nicotine, the Food and Drug Administration (FDA) lists the product as an electronic nicotine delivery system or ENDS device. Similar electronic devices can be used to vape cannabis extracts. Over the past decade, the vaping market has increased exponentially, raising health concerns over the number of people exposed and a nationwide outbreak of cases of severe, sometimes fatal, lung dysfunction that arose suddenly in otherwise healthy individuals. In this review, we discuss the various vaping technologies, which are remarkably diverse, and summarize the use prevalence in the U.S. over time by youths and adults. We examine the complex chemistry of vape carrier solvents, flavoring chemicals, and transformation products. We review the health effects from epidemiological and laboratory studies and, finally, discuss the proposed mechanisms underlying some of these health effects. We conclude that since much of the research in this area is recent and vaping technologies are dynamic, our understanding of the health effects is insufficient. With the rapid growth of ENDS use, consumers and regulatory bodies need a better understanding of constituent-dependent toxicity to guide product use and regulatory decisions.

Phytocannabinoids Biosynthesis in Angiosperms, Fungi, and Liverworts and Their Versatile Role

Phytocannabinoids are a structurally diverse class of bioactive naturally occurring compounds found in angiosperms, fungi, and liverworts and produced in several plant organs such as the flower and glandular trichrome of Cannabis sativa, the scales in Rhododendron, and oil bodies of liverworts such as Radula species; they show a diverse role in humans and plants. Moreover, phytocannabinoids are prenylated polyketides, i.e., terpenophenolics, which are derived from isoprenoid and fatty acid precursors. Additionally, targeted productions of active phytocannabinoids have beneficial properties via the genes involved and their expression in a heterologous host. Bioactive compounds show a remarkable non-hallucinogenic biological property that is determined by the variable nature of the side chain and prenyl group defined by the enzymes involved in their biosynthesis. Phytocannabinoids possess therapeutic, antibacterial, and antimicrobial properties; thus, they are used in treating several human diseases. This review gives the latest knowledge on their role in the amelioration of abiotic (heat, cold, and radiation) stress in plants. It also aims to provide synthetic and biotechnological approaches based on combinatorial biochemical and protein engineering to synthesize phytocannabinoids with enhanced properties.

Cannabis dabbing: An emerging trend

ABSTRACT

Cannabis dabbing refers to the recreational inhalation of extremely concentrated tetrahydrocannabinol, the main psychotropic cannabinoid derived from the marijuana plant. The practice carries significant health and legal risks. This article discusses what nurses need to know about dabbing and how they can educate patients who may be engaging in risky behavior.

Catatonia Related to Cannabis and Synthetic Cannabinoids: A Review

Cannabis and synthetic cannabinoids (SC) are related to several neuropsychiatric symptoms and disorders, especially psychotic symptoms and disorders. Interestingly, catatonia-like symptoms associated with cannabis and SC have been generally neglected in research and scarcely described despite the clinical repercussions. Hence, this review aims to analyze current clinical publications on catatonia induced by cannabis or SC in a systematized way. Methods: A search using PRISMA guidelines was performed on three databases based on a specific inclusion and exclusion criteria. Results: 11 publications describing 14 patients (10 males; mean age 22.50 ± 6.67 years old) with catatonia apparently precipitated by the use of cannabis (n = 6) or SC (n = 8) were found. Clinical features and treatment are described and discussed. Conclusion: From a clinical perspective, cannabis and SC use may be related to catatonia-like symptoms and catatonia syndrome in the same way these substances (cannabis and SC) are related to induced-psychotic episodes. However, further research will be required to understand the exact nature of that relationship. Additionally, investigations focused on the clinical significance (i.e., prognosis, evolution, and outcomes) of catatonia-like symptoms induced by cannabis and SC use in patients are also needed.

Adverse effects of Δ9-tetrahydrocannabinol on neuronal bioenergetics during postnatal development

Ongoing societal changes in views on the medical and recreational roles of cannabis increased the use of concentrated plant extracts with a Δ⁹-tetrahydrocannabinol (THC) content of more than 90%. Even though prenatal THC exposure is widely considered adverse for neuronal development, equivalent experimental data for young age cohorts are largely lacking. Here, we administered plant-derived THC (1 or 5 mg/kg) to mice daily during P5–P16 and P5–P35 and monitored its effects on hippocampal neuronal survival and specification by high-resolution imaging and iTRAQ proteomics, respectively. We found that THC indiscriminately affects pyramidal cells and both cannabinoid receptor 1⁺ (CB₁R)⁺ and CB₁R^– interneurons by P16. THC particularly disrupted the expression of mitochondrial proteins (complexes I–IV), a change that had persisted even 4 months after the end of drug exposure. This was reflected by a THC-induced loss of membrane integrity occluding mitochondrial respiration and could be partially or completely rescued by pH stabilization, antioxidants, bypassed glycolysis, and targeting either mitochondrial soluble adenylyl cyclase or the mitochondrial voltage-dependent anion channel. Overall, THC exposure during infancy induces significant and long-lasting reorganization of neuronal circuits through mechanisms that, in large part, render cellular bioenergetics insufficient to sustain key developmental processes in otherwise healthy neurons.

Repeated THC exposure in juvenile mice compromises the limbic circuitry, with life-long impairment to the respiration of neurons.

Cannabis health knowledge and risk perceptions among Canadian youth and young adults

Abstract

Background

Although recreational cannabis is now legal in Canada, little empirical evidence exists regarding young Canadians’ cannabis literacy, cannabis-related risk perceptions, and risk of different forms of cannabis or the effect that public health education may have on these perceptions. The present study sought to address these knowledge gaps to examine health knowledge and risk perceptions associated with cannabis use.

Methods

An online survey was conducted with a national sample (N = 870) of Canadians aged 16 to 30 years in October 2017 using a commercial panel. The study examined young Canadians’ awareness of negative health effects related to cannabis, evaluation of known risks, and risk perceptions of different forms of administration.

Results

Most respondents were aware of a cannabis-related physical health effect (78.0%). Approximately one-third reported having been exposed to public health messaging about cannabis; digital media was reported most frequently. Compared to never users, ever users were less likely to report general likelihood of addiction (p < 0.001) and harm to mental health (p < 0.001). Approximately one-quarter of past 3-month cannabis users reported they were at least “a little” addicted. Respondents who reported using a particular form of cannabis self-administration (e.g., edibles, smokables) were less likely to perceive harm than those who did not use each form (p < 0.001).

Conclusions

The current study is among the first to measure the knowledge and perceptions of risks of Canadian youth about cannabis. The study, conducted in the time immediately preceding legalization, may serve as a reference point for future studies examining changes in cannabis knowledge and risk perceptions. This will be important in addressing the need for monitoring and enhancing public awareness of the impact and potential harms of this newly legalized substance.

Assessing the public health impact of cannabis legalization in Canada: core outcome indicators towards an 'index' for monitoring and evaluation

The legalization of non-medical cannabis use and supply is impending in Canada. This constitutes a major policy change with the declared objective of improving public health outcomes, which requires rigorous monitoring and evaluation. While numerous different aspects associated with legalization will be examined, a focused perspective is required for effective policy evaluation purposes. To these ends, we have identified a set of 10 core indicators associated with cannabis-related risk/harm outcomes-based on current best evidence-that are expected to measure the primary impacts of legalization on public health outcomes. We briefly review these indicators, and their respective data availability in Canada. As ideally an integrated outcome assessment of cannabis legalization's impact on public health will be available, we further propose options to merge the individual indicators into an integrated, weighted 'index', considering their expected relative impact for public health. One possible approach to undertake this is 'multi-criteria decision analysis' as a method to weight the relative indicator impact on public health; alternative approaches are proposed. The integrated 'public health index' for cannabis legalization will allow for scientifically comprehensive, while focused, monitoring and evaluation of the effects of legalization in Canada for the benefits of science and evidence-based policy alike.

Cannabinoid Hyperemesis Syndrome: A Review of Potential Mechanisms

Introduction: Cannabinoids have long been known for their ability to treat nausea and vomiting. Recent reports, however, have highlighted the paradoxical proemetic effects of cannabinoids. Cannabinoid hyperemesis syndrome (CHS) is characterized by cyclical episodes of nausea and vomiting, accompanied by abdominal pain following prolonged, high-dose cannabis use, which is alleviated by hot baths and showers. Little is known about the cause of this syndrome. Discussion: Cannabinoids produce a biphasic effect on nausea and vomiting, with low doses having an antiemetic effect and high doses producing emesis. Presentation and treatment of CHS are similar to cyclical vomiting syndrome as well as chemotherapy-related anticipatory nausea and vomiting, suggesting that these phenomena may share mechanisms. The prevalence of CHS is not known because of the symptomatic overlap with other disorders and the lack of knowledge of the syndrome by the public and physicians. Treatment with typical antiemetic drugs is ineffective for CHS, but anxiolytic and sedative drugs, along with hot showers, seem to be consistently effective at reducing symptoms. The only known way to permanently end CHS, however, is abstinence from cannabinoids. Case studies and limited pre-clinical data on CHS indicate that prolonged high doses of the main psychotropic compound in cannabis, Δ9-tetrahydrocannabinol (THC), result in changes to the endocannabinoid system by acting on the cannabinoid 1 (CB1) receptor. These endocannabinoid system changes can dysregulate stress and anxiety responses, thermoregulation, the transient receptor potential vanilloid system, and several neurotransmitters systems, and are thus potential candidates for mediating the pathophysiology of CHS. Conclusions: Excessive cannabinoid administration disrupts the normal functioning of the endocannabinoid system, which may cause CHS. More clinical and pre-clinical research is needed to fully understand the underlying pathophysiology of this disorder and the negative consequences of prolonged high-dose cannabis use.

Modes of marijuana use - smoking, vaping, eating, and dabbing: Results from the 2016 BRFSS in 12 States

BACKGROUND

The prevalence of modes of marijuana use (e.g., smoked, vaped, eaten, dabbed, etc.), and of multi-modal use has not been assessed across multiple states, and can inform marijuana prevention and education work, given that certain modes of use are associated with specific public health risks. This study aimed to assess the prevalence of different modalities of reported marijuana use among adults in 12 states.

METHODS

Data came from 6174 adult marijuana users age 18 and older who responded to questions about past month and mode of marijuana use on the 2016 BRFSS surveys in 12 states with varied state marijuana policies. We used weighted frequencies for descriptive analyses, and logistic regression to identify correlates of multi-modal use.

RESULTS

The prevalence of past month (current) marijuana use among adults in these states was 9.1 % (males = 12.0 %, females= 6.3 %). Among current marijuana users, 33.7 % reported multiple methods of marijuana use, 90.1 % reported any marijuana smoking (e.g., joints, blunts, bongs, bowls), 58.3 % reported only smoking (no other modes of consumption), 24.5 % reported any edible use, 4.5 % reported using only edibles, 19.4 % reported any marijuana vaping, 2.1 % reported only vaping, 14.5 % reported any dabbing (flash vaporization/inhalation of highly concentrated marijuana), and 0.4 % reported only dabbing. Correlates of multimodal use are also examined.

CONCLUSION

Multi-modal use of marijuana is common, and use of non-smoked marijuana (edibles, vaping, dabbing) often occurs in conjunction with other modes of marijuana use. Ongoing surveillance of marijuana modes of use and multi-modal use is warranted to inform public education and prevention.

Modes of Marijuana Consumption Among Colorado High School Students Before and After the Initiation of Retail Marijuana Sales for Adults

OBJECTIVE

This study aimed to estimate the prevalence of different modes of marijuana consumption (e.g., smoking, ingesting) overall and by sociodemographic factors, marijuana-related perceptions, and other substance use among adolescents, as well as to characterize differences in the usual mode of consumption before and after the initiation of retail marijuana sales in 2014.

METHOD

Data are from the 2013 and 2015 administrations of the Healthy Kids Colorado Survey, a cross-sectional, school-based survey. We included 9th-12th grade students who reported past-30-day marijuana use in 2013 (n = 2,792; 44.8% female) or 2015 (n = 1,664; 48.9% female). We estimated the prevalence of any past-month use of each mode in 2015 and usual mode of consumption the past month in both years. We tested differences by year, sociodemographics, marijuana-related perceptions, and other substance use using Rao-Scott chi-square tests and multivariable logistic regression.

RESULTS

The prevalence of past-month marijuana use was 20.7% in both years. In 2015, 39.8% of students reported using multiple modes in the past month. Use of any mode other than smoking and use of multiple modes differed by sociodemographics, marijuana-related perceptions, and other substance use. Smoking remained the most common usual mode in 2015. The prevalence of usually ingesting significantly decreased from 4.7% to 2.1% between years, whereas "other mode(s)" significantly increased from 4.0% to 6.0%.

CONCLUSIONS

The use of multiple modes of marijuana consumption was prevalent among adolescents in Colorado. The usual mode of consumption changed in years before and after the implementation of retail marijuana sales, suggesting the need for continued surveillance.

Cannabis Butane Hash Oil Dabbing Induced Lung Injury Mimicking Atypical Pneumonia

"Dabbing" is the inhalation of concentrated marijuana, usually in butane solvent. This case report illustrates a previously healthy 25-year-old caucasian male with a 10-year history of cannabis butane hash oil (BHO) use. The patient presented with dyspnea and cough. The evaluation included a chest x-ray, basic laboratory investigations, computerized tomography angiogram of the chest and echocardiogram. Patient was diagnosed with acute lung injury mimicking atypical pneumonia. He was treated with steroids and had clinically improved and advised to stop dabbing. Further studies are needed to elucidate the full spectrum of the adverse effects of dabbing.

Acute Effects of Cannabis Concentrate on Motor Control and Speed: Smartphone-Based Mobile Assessment

Background: The use of cannabis concentrate is dramatically rising and sparking major safety concerns. Cannabis concentrate contains tetrahydrocannabinol (THC) potencies up to 90%, yet there has been little research on motor impairment after concentrate use (commonly referred to as "dabbing"). This study measured postural control and motor speed after the use of high potency concentrates in males and females. Methods: Experienced concentrate users (N = 65, Female: 46%, 17 ± 11 days/month of concentrate use) were assessed for motor performance in a mobile laboratory before, immediately after, and 1 h after ad-libitum cannabis concentrate use. Plasma levels of THC were obtained via venipuncture at each timepoint. We used a remotely deployable motor performance battery to assess arm and leg movement speed, index finger tapping rate, and balance. The sensors on a smart device (iPod Touch) attached to the participant provided quantitative measures of movement. Results: Arm speed slowed immediately after concentrate use and remained impaired after 1 h (p < 0.001), leg speed slowed 1 h after use (p = 0.033), and balance decreased immediately after concentrate use (eyes open: p = 0.017, eyes closed: p = 0.013) but not at 1 h post-use. These effects were not different between sexes and there was no effect of concentrate use on finger tapping speed. Acute changes in THC plasma levels after use of concentrates were minimally correlated with acute changes in balance performance. Conclusions: Use of cannabis concentrates in frequent users impairs movement speed and balance similarly in men and women. The motor impairment is largely uncorrelated with the change in THC plasma levels. These results warrant further refinement of cannabis impairment testing and encourage caution related to use of cannabis concentrates in work and driving settings.

Efficacy and adverse event profile of cannabidiol and medicinal cannabis for treatment-resistant epilepsy: Systematic review and meta-analysis

This paper aimed to systematically examine the efficacy and adverse event (AE) profile of cannabidiol and medicinal cannabis by analyzing qualitative and meta-analytic data. We used the terms ("Cannabidiol" OR "Cannabis") AND "Epilepsy" AND ("Treatment" OR "Therapeutics") as keywords to retrieve studies indexed on PubMed, ScienceDirect, and CENTRAL databases. The inclusion criteria were as follows: clinical studies with a longitudinal observational design and intervention using cannabinoid derivatives, especially cannabidiol and medicinal cannabis, whereby some results involved the frequency of epileptic seizures. We used Cochrane Collaboration's Review Manager software (RevMan 5.1.6) for the meta-analysis and dichotomized the articles to a confidence interval of 95%. From 236 articles, we selected 16 for descriptive analysis; we selected only 4 for the meta-analysis. According to the results, a statistically meaningful effect of cannabidiol compared with placebo was observed (p < 0.00001). When comparing treatment with cannabidiol or medicinal cannabis, significance was not found for the AE profile (p = 0.74). As AEs for cannabidiol were more common under short-term than under long-term treatment (p < 0.00001), this approach was favorable in the long term. Furthermore, cannabidiol is more effective than placebo, regardless of the etiology of epileptic syndromes and dosage. Overall, the AE profile did not differ across treatments with cannabidiol or medicinal cannabis, though it did differ favorably for long-term than for short-term treatment.

Beyond the Bud: Emerging Methods of Cannabis Consumption for Youth

Cannabis continues to be the most widely used illicit substance among youth, as many teens view the risks of cannabis consumption to be low. With cannabis laws becoming lax and dispensaries becoming more prevalent throughout the United States, highly concentrated Δ-9-tetrahydrocannibinol (THC) is becoming readily available. This article examines the available literature on consumption of concentrated THC, focusing on potential consequences of concentrate use among youth. Various methods for consuming concentrated THC, including ingestion of edibles, vaping, and dabbing, are discussed, along with associated risks of each consumption method. Recommendations for health professionals are provided.

Cingulate-basal ganglia-thalamo-cortical aspects of catatonia and implications for treatment

The catatonic syndrome is an example of a multifactorial neurobehavioral disorder that causes much morbidity and mortality but also has the potential to unlock the mystery of how motivation and movement interact to produce behavior. In this chapter, an attempt is made to understand better the catatonic syndrome through the lens of neurobiology and neuropathophysiology updated by recent studies in molecular biology, genomics, inflammasomics, neuroimaging, neural network theory, and neuropsychopathology. This will result in a neurostructural model for the catatonic syndrome that centers on paralimbic regions including the anterior and midcingulate cortices, as they interface with striatal and thalamic nodes in the salience decision-making network. Examination of neurologic disorders like the abulic syndrome, which includes in its extreme catatonic form, akinetic mutism, will identify the cingulate cortex and paralimbic neighbors as regions of interest. This exploration has the potential to unlock mysteries of the brain cascade from motivation to movement and to clarify catatonia therapeutics. Such a synthesis may also help us discern meaning inherent in this complex neurobehavioral syndrome.

Price and product variation in Washington's recreational cannabis market

BACKGROUND

Ten U.S. states, Canada, and Uruguay have passed laws to legalize the production and sale of cannabis for non-medical purposes. Available research has documented rapidly falling prices and changing product mixes, but many details are not well understood: particularly, the popularity, prices, and product characteristics of different cannabis edibles and extract-based products - each offering different ways to consume cannabis, with unclear health consequences.

METHODS

This paper analyzes data from Washington's recreational cannabis market, which has recorded over 110 million retail item-transactions from July 2014 to October 2017. Previous research on price and product trends has focused mostly on herbal cannabis, which accounts for the majority, but a decreasing share, of sales. This paper applies advanced text-analytic methods to provide new insights, including (A) estimating potency data for edibles and (B) identifying extract sub-types. Patterns and trends are described, across product types, regarding THC and CBD profiles and price per THC.

RESULTS

Extracts accounted for 28.5% of sales in October 2017. Of extracts categorized to subtype, nearly half were identified as "dabs", and another half "cartridges". In October 2017, price per 10 mg THC was roughly $3 among edibles, 70 cents among extract cartridges, and 30-40 cents for other flower and other extracts; solid concentrates offered the lowest priced THC among extract products. Price declines continue but have slowed. High-CBD chemovars are becoming more common, but still are almost non-existent in flower marijuana and rare (1% of sales) among extract products.

CONCLUSION

As Washington's recreational cannabis market has developed over three and a half years, trends identified in that market may serve as an early indication of potential issues in other states. Legislators and regulators in other jurisdictions with commercial non-medical cannabis markets may wish to establish policies responsive to these trends in product popularity, price, and potency.

Cannabis Concentrate Use in Adolescents

BACKGROUND

Cannabis concentrates, which are cannabis plant extracts that contain high concentrations of Δ-9-tetrahydrocannbinol (THC), have become increasingly popular among adults in the United States. However, no studies have reported on the prevalence or correlates of cannabis concentrate use in adolescents, who, as a group, are thought to be particularly vulnerable to the harms of THC.

METHODS

Participants are a racially and ethnically diverse group of 47 142 8th-, 10th-, and 12th-grade students recruited from 245 schools across Arizona in 2018. Participants reported on their lifetime and past-month marijuana and cannabis concentrate use, other substance use, and risk and protective factors for substance use problems spanning multiple life domains (ie, individual, peer, family, school, and community).

RESULTS

Thirty-three percent of all 8th-, 10th-, and 12th-graders reported lifetime cannabis use, and 24% reported lifetime concentrate use. Seventy-two percent of all lifetime cannabis users had used concentrates. Relative to adolescent cannabis users who had not used concentrates, adolescent concentrate users were more likely to use other substances and to experience more risk factors, and fewer protective factors, for substance use problems across numerous life domains.

CONCLUSIONS

Most adolescent cannabis users have used concentrates. Based on their risk and protective factor profile, adolescent concentrate users are at higher risk for substance use problems than adolescent cannabis users who do not use concentrates. Findings raise concerns about high-risk adolescents' exposure to high-THC cannabis.

Cannabidiol (CBD) use in psychiatric disorders: A systematic review

Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the most represented phytocannabinoids in Cannabis sativa plants. However, CBD may present with a different activity compared with the psychotomimetic THC. Most typically, CBD is reported to be used in some medical conditions, including chronic pain. Conversely, the main aim of this systematic review is to assess and summarise the available body of evidence relating to both efficacy and safety of CBD as a treatment for psychiatric disorders, alone and/or in combination with other treatments. Eligible studies included randomized controlled trials (RCT) assessing the effect of CBD in a range of psychopathological conditions, such as substance use; psychosis, anxiety, mood disturbances, and other psychiatric (e.g., cognitive impairment; sleep; personality; eating; obsessive-compulsive; post-traumatic stress/PTSD; dissociative; and somatic) disorders. For data gathering purposes, the PRISMA guidelines were followed. The initial search strategy identified some n = 1301 papers; n = 190 studies were included after the abstract's screening and n = 27 articles met the inclusion criteria. There is currently limited evidence regarding the safety and efficacy of CBD for the treatment of psychiatric disorders. However, available trials reported potential therapeutic effects for specific psychopathological conditions, such as substance use disorders, chronic psychosis, and anxiety. Further large-scale RCTs are required to better evaluate the efficacy of CBD in both acute and chronic illnesses, special categories, as well as to exclude any possible abuse liability.

Frequently asked questions about dabbing concentrates in online cannabis community discussion forums

BACKGROUND

"Dabbing" involves vaporizing a "dab" of cannabis concentrate on a heated "nail," passing the vapour through a water-pipe rig or portable pen device, and inhaling the vapour. While some cannabis industry media claims that this process is cleaner, safer, and more effective for getting high, medical and public health sources raise concerns about residual solvents and pesticides, unexpectedly intense effects, and rapid increases in tolerance. The aim of this study is to characterize the content of questions about dabbing posed in cannabis and dabbing-specific forums on the Reddit social media platform, as well as comment responses to these questions.

METHODS

We conducted a content analysis of one year (2017) of information-seeking user-generated posts to three Reddit online cannabis community discussion forums ("subreddits") that contained the terms "dab" and "question." We also examined post engagement and the types and sentiment of information exchanged in the comment responses.

RESULTS

Across 193 dabbing question posts, the most frequently asked question content was about types and logistical use of devices and related equipment (38%) and comparisons of cannabis products (32%), followed by questions about the step-by-step process of getting high (18%), legal issues (17%), and health concerns (13%). Nearly every post had a response (98%), with a median 5 comments per post and few negative (i.e. hostile, condescending, or trolling) comments (4%). Source of advice or information was stated in about a quarter (26%) of comment responses, with the overwhelming majority of this information (89%) coming from disclosures of personal experience vs. web or commercial sources.

CONCLUSION

People seeking advice online about dabbing inquired most often about logistics of use, but less often about health, tolerance, and legal risks. These findings may be used to inform public health efforts and health practitioner education as cannabis becomes increasingly legal and accessible.

Cannabis use patterns at the dawn of US cannabis reform

In the United States (US), three in 10 cannabis users develop cannabis use disorder (CUD). Usage patterns in line with CUD may be associated with socio-economic disadvantage, and other negative effects. Thus, research on CUD is paramount. To provide understanding around CUD, it is necessary to detail granular cannabis usage preferences, as some risk from cannabis use may be mitigated through informed behavioral choices by users. We describe cannabis usage preferences among US Global Drug Survey (GDS) respondents, primarily young men. The cross-sectional web-based GDS (2017) was completed by 8345 US-resident respondents (median age = 23, Interquartile Range 19–32; % male = 75.48) who reported cannabis use. Of those who reported cannabis use in the past year, most (78%) reported consuming their first joint more than an hour after waking, and about half the sample (49%) had their last joint 1–2 h before bed. Cannabis was used for a median of 250 days in the last year (almost daily). Respondents spent a median of four hours a day stoned when cannabis was used. High potency herbal cannabis was the preferred variant by 62% of participants. We suggest that frequent use of cannabis may increase risk of health harms, and highlight the need to mitigate problematic use. With the rapidly developing US cannabis market, possibly problematic usage patterns may indicate potential for CUD especially within young men.

Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects

Cannabis legalization has led to significant health consequences, particularly to patients in emergency departments and hospitals in Colorado. The most concerning include psychosis, suicide, and other substance abuse. Deleterious effects on the brain include decrements in complex decision-making, which may not be reversible with abstinence. Increases in fatal motor vehicle collisions, adverse effects on cardiovascular and pulmonary systems, inadvertent pediatric exposures, cannabis contaminants exposing users to infectious agents, heavy metals, and pesticides, and hash-oil burn injuries in preparation of drug concentrates have been documented. Cannabis dispensary workers (“budtenders”) without medical training are giving medical advice that may be harmful to patients. Cannabis research may offer novel treatment of seizures, spasticity from multiple sclerosis, nausea and vomiting from chemotherapy, chronic pain, improvements in cardiovascular outcomes, and sleep disorders. Progress has been slow due to absent standards for chemical composition of cannabis products and limitations on research imposed by federal classification of cannabis as illegal. Given these factors and the Colorado experience, other states should carefully evaluate whether and how to decriminalize or legalize non-medical cannabis use.

A cross-sectional examination of choice and behavior of veterans with access to free medicinal cannabis

Background: With a rise in public pressure to increase veteran access to medicinal cannabis, free cannabis collectives for military veterans are proliferating across the US. Objectives: The aim of the current study was to document which cannabis formulations and routes of administration are chosen by veterans with increased access to cannabis, and to determine whether cannabis is being used as a substitute for other licit and illicit drugs. Method: The current study collected cross-sectional self-report data on cannabis use, cannabinoid constituent composition, primary indication of use, and substitution practices among a sample of 93 US military veterans (84.9% male) with access to free cannabis. Result: Most of the sample reported using cannabinoids as a substitute for either alcohol, tobacco, prescription medications, or illicit substances, reported that they use cannabis frequently (Modal frequency >4x/day, Modal quantity = 5 to 8 grams/week), and primarily select higher-risk cannabis formulations (i.e., high THC/low CBD, smoked). The majority of the sample reported that they use cannabis to self-treat multiple physical and mental health conditions/symptoms. Conclusions: Results of the current study suggest that military Veterans with reduced barriers to access cannabis could be making both helpful and harmful choices regarding their cannabis use. These findings suggest that more guidance on the selection of cannabis-based products in this population is warranted, particularly as barriers to medicinal cannabis access are reduced.

A review of the anesthetic implications of marijuana use

Marijuana, derived from plants of the genus Cannabis, is the most commonly used illicit drug in the United States. Marijuana is illegal at the federal level and remains a Drug Enforcement Agency Schedule 1 substance. Nevertheless, most states have passed less stringent legislation related to its use, ranging from decriminalization of possession to allowing medical or even recreational use, and some county and municipal law enforcement agencies have refrained from prosecuting personal possession and/or use even when statute would require such action. Therefore, as use of marijuana becomes more common in the larger population, more patients who are chronic and/or heavy users of marijuana present for surgical procedures, raising the question of best practices to care for these patients in the perioperative period. This review summarizes the known physiologic effects of marijuana in humans, discusses potential implications of marijuana use that the anesthesiologist should consider at each phase of the perioperative period, and outlines recommendations for future study.

Butane hash oil and dabbing: insights into use, amateur production techniques, and potential harm mitigation

The use of marijuana concentrates has escalated in recent years with butane extracts appearing particularly popular. The administration of butane hash oil, colloquially referred to as “dabbing,” is distinct from traditional flower cannabis usage due to the THC content of samples and the presence of impurities such as unpurged butane. While this may confer heightened risk to the user, additional significant concerns are tied to fires and explosions. Using butane as a solvent in amateur “blasting” methods may result in a flammable vapor pooling in enclosed spaces and igniting when exposed to a spark. As research on butane extract users, amateur production techniques, health risks, and legality is in its infancy, we explored existing studies on the topic to create a review of substantiated knowledge related to THC extracted using butane. The resulting assessment centers on three areas: 1) dab users including both recreational users and medical marijuana patients; 2) butane extraction techniques including illicit amateur open methods and the safer closed-loop system employed in medicinal/recreational states; and 3) risks, both related to fires and legality. We follow the presentation of this material with a summary of the (mis)information reaching the public in print and online sources so that public educational campaigns can focus on dispelling the inaccuracies and false notions of safety that may be tied to amateur production.

Made from concentrate? A national web survey assessing dab use in the United States

BACKGROUND

Cannabis concentrates, including dabs, contain extremely high levels of Δ⁹-tetrahydrocannabinol (THC). Although these products appear to be gaining popularity among recreational cannabis consumers, little data exists regarding concentrate use in the US. We conducted a national web-based survey to examine patterns of concentrate use, specifically dabbing.

METHODS

4077 respondents completed a survey designed to assess the use of conventional flower cannabis relative to dabs. Individuals provided information about frequency and magnitude of use, and also completed the Marijuana Motives Measure and Severity of Dependence Scale to examine whether dab users have different motives for use and/or demonstrate more severe consequences of use compared to those who only use conventional flower products.

RESULTS

58% of respondents reported they had tried dabs at least once and 36.5% endorsed regular use (once a month or more). Those who use regularly use dabs were significantly more likely to report using for experimentation (feeling "curious") relative to reasons for using conventional flower products. Interestingly, motives reflecting positive effects (i.e., coping, sleep problems, relieving social anxiety) were endorsed more highly for flower use. In addition, regular dab users reported being more worried about their use of cannabis products relative to those who had tried dabs but did not use regularly.

CONCLUSIONS

Results indicate that cannabis consumers do not necessarily choose dabs over flower products for positive effects, but rather appear to choose these highly potent products for experimentation. As concentrate use may lead to increased cannabis-related problems, studies directly assessing concentrate users are needed.

Cannabinoids: from pot to lab

Cannabis is becoming increasingly present in our society. In recent years, the line between the natural (cannabis) and the synthetic (synthetic cannabinoids), the recreational (cannabis) and the medical (pharmaceutical cannabinoids and medical cannabis) has been crossed. In this paper we review some of the novel aspects of cannabis and cannabinoids in relation to their legal situation, changes in their composition and forms of cannabis use, the concept of medical cannabis, and synthetic cannabinoids as new psychoactive substances (NPS). We have also analyzed serious adverse reactions and intoxications associated with the use of synthetic cannabinoids, as well as the latest developments in the research of pharmaceutical cannabinoids.

Cannabis regulatory science: risk-benefit considerations for mental disorders

The evolving legal cannabis landscape in the US continues to present novel regulatory challenges that necessitate the development of a Cannabis Regulatory Science. Two specific issues of concern within Cannabis Regulatory Science are (1) the impact that cannabis use has on the incidence, prevalence, and severity of mental disorders, and (2) how cannabis laws and regulations modify this impact. This paper first provides several conceptual points that are useful for evaluating the relationship between cannabis use and mental disorders. Second, it selectively reviews and comments on data relevant to the relationship between cannabis use and depression, several forms of anxiety, post-traumatic stress disorder, schizophrenia, and bipolar disorder. Next, regulatory and public health parallels between the nascent cannabis industry and the pharmaceutical, tobacco, and alcohol industries are discussed. The focus is on specific types of industry practices that may harm those with or at risk for mental disorders. Recommendations are then offered for legal cannabis regulations that could mitigate this harm. Last, future research goals are discussed for building the field of Cannabis Regulatory Science and addressing the potential negative impact of cannabis on those with mental disorders.

A Twitter-based survey on marijuana concentrate use

AIMS

The purpose of this paper is to analyze characteristics of marijuana concentrate users, describe patterns and reasons of use, and identify factors associated with daily use of concentrates among U.S.-based cannabis users recruited via a Twitter-based online survey.

METHODS

An anonymous Web-based survey was conducted in June 2017 with 687 U.S.-based cannabis users recruited via Twitter-based ads. The survey included questions about state of residence, socio-demographic characteristics, and cannabis use including marijuana concentrates. Multiple logistic regression analyses were conducted to identify characteristics associated with lifetime and daily use of marijuana concentrates.

RESULTS

Almost 60% of respondents were male, 86% were white, and the mean age was 43.0 years. About 48% reported marijuana concentrate use. After adjusting for multiple testing, significant predictors of concentrate use included: living in "recreational" (AOR = 2.04; adj. p = .042) or "medical, less restrictive" (AOR = 1.74; adj. p = .030) states, being younger (AOR = 0.97, adj. p = .008), and daily herbal cannabis use (AOR = 2.57, adj. p = .008). Out of 329 marijuana concentrate users, about 13% (n = 44) reported daily/near daily use. Significant predictors of daily concentrate use included: living in recreational states (AOR = 3.59, adj. p = .020) and using concentrates for therapeutic purposes (AOR = 4.34, adj. p = .020).

CONCLUSIONS

Living in states with more liberal marijuana policies is associated with greater likelihood of marijuana concentrate use and with more frequent use. Characteristics of daily users, in particular, patterns of therapeutic use warrant further research with community-recruited samples.

Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods

One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.

Regulating Cannabis Manufacturing: Applying Public Health Best Practices from Tobacco Control

State legalization and regulation of cannabis, despite continued federal illegality, is a massive shift in regulatory approach. Manufactured cannabis, including concentrates, extracts, edibles, tinctures, topicals and other products, has received less attention than more commonly used dried flower, but represents emerging regulatory challenges due to additives, potency, consumption methods, and abuse and misuse potential. In November 2017, the California Department of Public Health (CDPH) released initial cannabis manufacturing regulations as part of a new state regulatory structure. As the largest U.S. medical cannabis market (and largest legal adult use market in the world beginning in 2018), California's regulatory approach will potentially influence national and global policy. Comparing CDPH's initial regulations to tobacco control best practices reveals that, while the regulations recognize the need to protect public health, prioritizing public health over business interests requires stronger approaches to labeling, packaging, and product formulations. Based on tobacco best practices, we recommend that cannabis regulations incorporate large and proportionately sized informational labels, a prominent universal cannabis symbol, rotating and pictorial health warnings, mandatory plain packaging, a comprehensive ban on characterizing flavors and addictive additives, and strict limits on the potency of inhalable products and those easily confused with non-cannabis products.

A latent class analysis of poly-marijuana use among young adults

INTRODUCTION

With more states legalizing marijuana use, the marijuana industry has grown, introducing a variety of marijuana products. Our study explores the use of multiple marijuana products (poly-marijuana use) and the characteristics associated with this behavior.

METHODS

Past-month marijuana users aged 18-34years were surveyed online via an existing online panel (n=2444). Participants answered questions about past-month use of three types of marijuana (plant-based, concentrates, edibles), marijuana use patterns, and driving after use. Latent class analysis was used to identify subgroups of marijuana users.

RESULTS

Four classes of marijuana users were identified: Light plant users, who used only plant-based products infrequently and were unlikely to drive after use (32%); Heavy plant users, who used mainly plant-based products frequently, multiple times per day, and were likely to drive after use (37%); Plant and concentrates users, who used plant-based products heavily and concentrates at least infrequently, used multiple times per day, and were likely to drive after use (20%); Light plant and edibles users, who used both products infrequently and were unlikely to drive after use (10%). Those in legal marijuana states were more likely to belong to the poly-marijuana groups.

DISCUSSION

Our findings reflect the increase in popularity of new marijuana products in legal states and suggest that heavy user groups, including concentrates users, are associated with driving after use. As various forms of marijuana use increases, monitoring and surveillance of the use of multiple types of marijuana will be important for determining potential varying impacts on physiological and social consequences.

Legal cannabis laws, home cultivation, and use of edible cannabis products: A growing relationship?

BACKGROUND

Over half of U.S. states have enacted legal cannabis laws (LCL). In parallel, edible cannabis products (i.e., edibles) have presented new regulatory challenges. LCL provisions that dictate access to cannabis (e.g., home cultivation (HC) or dispensaries (DSP)) may impact edible production and use. This study examined relationships among HC and DSP provisions, cannabis cultivation, and edible use.

METHODS

An online cannabis use survey was distributed using Facebook. Data were collected from 1813 cannabis-using adults. U.S. states were classified as states without LCL (Non-LCL) or LCL states that: (1) only permit DSP (LCL DSP-only), (2) only permit HC (LCL HC-only), or (3) permit HC and DSP (LCL HC+DSP). Analyses tested associations among these classifications, cannabis growing, and edible use and procurement.

RESULTS

Individuals in LCL HC-only and LCL HC+DSP states were more likely to report currently growing cannabis at home (OR: 3.3, 95% CI: 1.7, 6.2; OR: 3.9, 95% CI: 2.4, 6.3, respectively) and past-month edible use (OR: 2.1, 95% CI: 1.4, 3.4; OR: 2.9, 95% CI: 2.2, 3.9, respectively) than individuals in LCL DSP-only states. Regardless of state, those who had grown cannabis were more likely to have made edibles than those who had never grown cannabis (OR: 2.2, 95% CI: 1.8, 2.6). Individuals in LCL HC-only states were more likely to have made edibles in the past month than individuals from Non-LCL (OR: 2.75, 95% CI: 1.5, 5.3) and DSP-only states (OR: 2.1, 95% CI: 1.0, 4.4). Individuals in LCL HC+DSP states were more likely to have purchased edibles in the past month than individuals from Non-LCL (OR: 3.7, 95% CI: 2.4, 5.6) and DSP-only states (OR: 3.2, 95% CI: 1.8, 5.5).

CONCLUSION

Specific LCL provisions may differentially affect individuals' propensity to grow cannabis and make, buy, and use edible cannabis products. Permitting home cultivation contributes to a greater likelihood of growing cannabis. Those who grow cannabis economize the plant by creating homemade edible cannabis products. Conversely, permitting dispensaries increases the likelihood of purchasing edibles. The psychoactive effects of edibles with unknown and variable cannabinoid content will be unpredictable. Policymakers should carefully consider how specific LCL provisions can affect patterns of cannabis edible product access and quality.

Associations between butane hash oil use and cannabis-related problems

BACKGROUND

High-potency cannabis concentrates are increasingly popular in the United States, and there is concern that use of high-potency cannabis might increase risk for cannabis-related problems. However, little is known about the potential negative consequences of concentrate use. This study reports on associations between past-year use of a high-potency cannabis concentrate, known as butane hash oil (BHO), and cannabis-related problems.

METHODS

A sample of 821 college students were recruited to complete a survey about their health and behavior. Participants who had used cannabis in the past year (33%, n=273) completed questions about their cannabis use, including their use of BHO and cannabis-related problems in eight domains: physical dependence, impaired control, academic-occupational problems, social-interpersonal problems, self-care problems, self-perception, risk behavior, and blackouts.

RESULTS

Approximately 44% (n=121) of past-year cannabis users had used BHO in the past year. More frequent BHO use was associated with higher levels of physical dependence (RR=1.8, p<0.001), impaired control (RR=1.3, p<0.001), cannabis-related academic/occupational problems (RR=1.5, p=0.004), poor self-care (RR=1.3, p=0.002), and cannabis-related risk behavior (RR=1.2, p=0.001). After accounting for sociodemographic factors, age of onset of cannabis use, sensation seeking, overall frequency of cannabis use, and frequency of other substance use, BHO use was still associated with higher levels of physical dependence (RR=1.2, p=0.014).

CONCLUSIONS

BHO use is associated with greater physiological dependence on cannabis, even after accounting for potential confounders. Longitudinal research is needed to determine if cannabis users with higher levels of physiological dependence seek out BHO and/or if BHO use increases risk for physiological dependence.

Toxicant Formation in Dabbing: The Terpene Story

Inhalable, noncombustible cannabis products are playing a central role in the expansion of the medical and recreational use of cannabis. In particular, the practice of "dabbing" with butane hash oil has emerged with great popularity in states that have legalized cannabis. Despite their growing popularity, the degradation product profiles of these new products have not been extensively investigated. The study herein focuses on the chemistry of myrcene and other common terpenes found in cannabis extracts. Methacrolein, benzene, and several other products of concern to human health were formed under the conditions that simulated real-world dabbing. The terpene degradation products observed are consistent with those reported in the atmospheric chemistry literature.

To Dab or Not to Dab: Rising Concerns Regarding the Toxicity of Cannabis Concentrates

Cannabis use is steadily rising in the United States. As the popularity of marijuana rises, new varieties of cannabis-related products are becoming available. Dabs are cannabis concentrates gaining notoriety for their significant amounts of tetrahydrocannabinol (THC) that are ultimately vaporized and inhaled for their effect. Herein, we provide an overview of recent cases of dabbing to bring awareness to the clinicians, of the significant adverse effects associated with dabs including psychosis, neurotoxicity, and cardiotoxicity.

Lower-Risk Cannabis Use Guidelines: A Comprehensive Update of Evidence and Recommendations

BACKGROUND

Cannabis use is common in North America, especially among young people, and is associated with a risk of various acute and chronic adverse health outcomes. Cannabis control regimes are evolving, for example toward a national legalization policy in Canada, with the aim to improve public health, and thus require evidence-based interventions. As cannabis-related health outcomes may be influenced by behaviors that are modifiable by the user, evidence-based Lower-Risk Cannabis Use Guidelines (LRCUG)-akin to similar guidelines in other health fields-offer a valuable, targeted prevention tool to improve public health outcomes.

OBJECTIVES

To systematically review, update, and quality-grade evidence on behavioral factors determining adverse health outcomes from cannabis that may be modifiable by the user, and translate this evidence into revised LRCUG as a public health intervention tool based on an expert consensus process.

SEARCH METHODS

We used pertinent medical search terms and structured search strategies, to search MEDLINE, EMBASE, PsycINFO, Cochrane Library databases, and reference lists primarily for systematic reviews and meta-analyses, and additional evidence on modifiable risk factors for adverse health outcomes from cannabis use.

SELECTION CRITERIA

We included studies if they focused on potentially modifiable behavior-based factors for risks or harms for health from cannabis use, and excluded studies if cannabis use was assessed for therapeutic purposes.

DATA COLLECTION AND ANALYSIS

We screened the titles and abstracts of all studies identified by the search strategy and assessed the full texts of all potentially eligible studies for inclusion; 2 of the authors independently extracted the data of all studies included in this review. We created Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow-charts for each of the topical searches. Subsequently, we summarized the evidence by behavioral factor topic, quality-graded it by following standard (Grading of Recommendations Assessment, Development, and Evaluation; GRADE) criteria, and translated it into the LRCUG recommendations by the author expert collective on the basis of an iterative consensus process.

MAIN RESULTS

For most recommendations, there was at least "substantial" (i.e., good-quality) evidence. We developed 10 major recommendations for lower-risk use: (1) the most effective way to avoid cannabis use-related health risks is abstinence, (2) avoid early age initiation of cannabis use (i.e., definitively before the age of 16 years), (3) choose low-potency tetrahydrocannabinol (THC) or balanced THC-to-cannabidiol (CBD)-ratio cannabis products, (4) abstain from using synthetic cannabinoids, (5) avoid combusted cannabis inhalation and give preference to nonsmoking use methods, (6) avoid deep or other risky inhalation practices, (7) avoid high-frequency (e.g., daily or near-daily) cannabis use, (8) abstain from cannabis-impaired driving, (9) populations at higher risk for cannabis use-related health problems should avoid use altogether, and (10) avoid combining previously mentioned risk behaviors (e.g., early initiation and high-frequency use).

AUTHORS' CONCLUSIONS

Evidence indicates that a substantial extent of the risk of adverse health outcomes from cannabis use may be reduced by informed behavioral choices among users. The evidence-based LRCUG serve as a population-level education and intervention tool to inform such user choices toward improved public health outcomes. However, the LRCUG ought to be systematically communicated and supported by key regulation measures (e.g., cannabis product labeling, content regulation) to be effective. All of these measures are concretely possible under emerging legalization regimes, and should be actively implemented by regulatory authorities. The population-level impact of the LRCUG toward reducing cannabis use-related health risks should be evaluated. Public health implications. Cannabis control regimes are evolving, including legalization in North America, with uncertain impacts on public health. Evidence-based LRCUG offer a potentially valuable population-level tool to reduce the risk of adverse health outcomes from cannabis use among (especially young) users in legalization contexts, and hence to contribute to improved public health outcomes.

Cannabis-associated psychosis: Neural substrate and clinical impact

Prospective epidemiological studies have consistently demonstrated that cannabis use is associated with an increased subsequent risk of both psychotic symptoms and schizophrenia-like psychoses. Early onset of use, daily use of high-potency cannabis, and synthetic cannabinoids carry the greatest risk. The risk-increasing effects are not explained by shared genetic predisposition between schizophrenia and cannabis use. Experimental studies in healthy humans show that cannabis and its active ingredient, delta-9-tetrahydrocannabinol (THC), can produce transient, dose-dependent, psychotic symptoms, as well as an array of psychosis-relevant behavioral, cognitive and psychophysiological effects; the psychotogenic effects can be ameliorated by cannabidiol (CBD). Findings from structural imaging studies in cannabis users have been inconsistent but functional MRI studies have linked the psychotomimetic and cognitive effects of THC to activation in brain regions implicated in psychosis. Human PET studies have shown that acute administration of THC weakly releases dopamine in the striatum but that chronic users are characterised by low striatal dopamine. We are beginning to understand how cannabis use impacts on the endocannabinoid system but there is much still to learn about the biological mechanisms underlying how cannabis increases risk of psychosis. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".

Marijuana advertising exposure among current marijuana users in the U.S

BACKGROUND

Little is known about marijuana advertising exposure among users in the U.S. We examined the prevalence of advertising exposure among young adult marijuana users through traditional and new media, and identified characteristics associated with seeking advertisements.

METHODS

We conducted a cross-sectional survey of 18-34 year-old past-month marijuana users in the U.S. using a pre-existing online panel (N=742). The survey queried about passively viewing and actively seeking marijuana advertisements in the past month, sources of advertisements, and marijuana use characteristics.

RESULTS

Over half of participants were exposed to marijuana advertising in the past month (28% passively observed advertisements, 26% actively sought advertisements). Common sources for observing advertisements were digital media (i.e., social media, online, text/emails; 77%). Similarly, those actively seeking advertisements often used Internet search engines (65%) and social media (53%). Seeking advertisements was more common among those who used medically (41% medical only, 36% medical and recreational) than recreational users (18%), who used concentrates or edibles (44% and 43%) compared to those who did not (20% and 19%), and who used multiple times per day (33%) compared to those who did not (19%) (all p<0.01).

CONCLUSIONS

Exposure to marijuana advertising among users is common, especially via digital media, and is associated with medical use, heavier use, and use of novel products with higher THC concentrations (i.e., concentrates) or longer intoxication duration (i.e., edibles). As the U.S. marijuana policy landscape changes, it will be important to examine potential causal associations between advertising exposure and continuation or frequency/quantity of use.