Intensity of cannabis use: Findings from three online surveys

Cannabis use and its association with psychopathological symptoms in a Swiss adult population: a cross-sectional analysis

Background

As the most commonly used illicit substance, cannabis is gaining global acceptance through increasing legalization efforts. This shift intensifies the need for research to guide policymakers and healthcare providers in harm reduction and treatment strategies. Nonetheless, the relationship between psychopathological symptoms and cannabis use remains inadequately understood.

Methods

A sample of regular cannabis consumers completed self-reported assessments for depression (Patient Health Questionnaire-9), anxiety (General Anxiety Disorder-7), Attention-Deficit/Hyperactivity Disorder (ADHD; Adult ADHD Self-Report Scale V1.1), and psychosis (Early Recognition Inventory based on IRAOS) as well as previous black-market cannabis use patterns. Cannabis Use Disorder Identification Test Revised (CUDIT-R) was used to identify cannabis use disorder (CUD). To understand psychopathological symptom load related to cannabis consumption as well as cannabis use motives, multiple regression models were performed to identify psychopathological variables predicting cannabis use frequency and quantity. Linear regression and correlation analyses were conducted, adjusting for relevant covariates (age, gender, education, alcohol, other substance use).

Results

Three-hundred-sixty regular cannabis users interested in a study on regulated cannabis access in Basel, Switzerland were examined. In bivariate analysis, cannabis use frequency correlated with depressive (r(358) = 0.16, p = 0.003) and anxiety symptom load (r(358) = 0.11, p = 0.034). Cannabis quantity correlated with depressive (r(358) = 0.15, p = 0.005), ADHD (r(358) = 0.14, p = 0.008), and psychosis symptom load (r(358) = 0.16, p = 0.002). However, in the adjusted regression models only depressive and ADHD symptom loads were significantly associated with cannabis use frequency (p = 0.006 and p = 0.034, respectively) and quantity (p = 0.037 and p = 0.019, respectively). No significant correlations between cannabis consumption and anxiety or psychosis remained after adjustment.

Conclusion

ADHD and depressive symptoms correlate with increased cannabis use in a cohort of regular users, suggesting potential self-medication in nonclinical populations. With the rising availability of cannabis worldwide, these results highlight the necessity for longitudinal studies to disentangle the complex dynamics between cannabis consumption and mental health symptoms.

Elemental Composition of Commercially Available Cannabis Rolling Papers

With the recent legalization of cannabis in multiple jurisdictions and widespread use as a medical treatment, there has been an increased focus on product safety and the potential impacts of contaminants on human health. One factor that has received little attention is the possible exposure to potentially hazardous levels of toxic elements from rolling (smoking) papers. The elemental composition of rolling papers is largely unregulated, with a minority of jurisdictions regulating papers only when they are part of a final cannabis product. This study reports the concentrations of 26 elements in commercially available rolling papers and estimates potential maximum exposures relative to USP232 and ICH Q3D dosages in pharmaceutical compounds. Exposure estimates indicate that the concentrations of several elements in some products, particularly Cu, Cr, and V, may present a potential hazard to frequent users. Several elements, including Ag, Ca, Ba, Cu, Ti, Cr, Sb, and possibly others, are likely present in elevated quantities in some papers due to product design and manufacturing processes. Our results further suggest that Cu-based pigments are used by a number of manufacturers and that regular use of these products might result in exposures as high as 4.5-11 times the maximum exposure limits. Further research to quantify the contribution of rolling papers to elemental exposure under realistic smoking conditions is warranted.

Individual differences in legal and illicit cannabis purchasing behaviour in British Columbia, Canada: Findings from a 2021 cross-sectional survey

BACKGROUND

Despite thousands of licensed cannabis retail stores operating across Canada, there remains a significant illicit cannabis market. Some cannabis users continue to buy cannabis from dealers, illicit stores, and/or illicit online retailers.

METHODS

Data are from the 2021 British Columbia Cannabis Use Survey. Respondents (n = 8473) were 19 years or older, lived in British Columbia at the time of the survey, and reported using cannabis in the past 12 months.

RESULTS

Buying cannabis from all types of illicit sources was more common among younger cannabis users, those who use cannabis more frequently and started using cannabis before the age of 17 (vs. 19 or older), and among those who co-use cannabis with other drugs. Specifically, buying cannabis from a dealer was more common among men, those with lower educational attainment, and those who seek the lowest prices when buying cannabis. In contrast, those using cannabis for medical (vs. non-medical) purposes were more likely to report getting cannabis from illicit retail stores, while buying cannabis from illicit websites was more common among people who use edible cannabis products.

CONCLUSION

Consistent with other studies, younger and more frequent cannabis users were more likely to report buying cannabis from illicit sources. However, these findings suggest there is significant heterogeneity among those who buy cannabis from different types of illicit sources, which should be carefully considered when developing policies and strategies aimed at encouraging consumers to transition to legal sources.

Association between cannabis use disorder and schizophrenia stronger in young males than in females

BACKGROUND

Previous research suggests an increase in schizophrenia population attributable risk fraction (PARF) for cannabis use disorder (CUD). However, sex and age variations in CUD and schizophrenia suggest the importance of examining differences in PARFs in sex and age subgroups.

METHODS

We conducted a nationwide Danish register-based cohort study including all individuals aged 16-49 at some point during 1972-2021. CUD and schizophrenia status was obtained from the registers. Hazard ratios (HR), incidence risk ratios (IRR), and PARFs were estimated. Joinpoint analyses were applied to sex-specific PARFs.

RESULTS

We examined 6 907 859 individuals with 45 327 cases of incident schizophrenia during follow-up across 129 521 260 person-years. The overall adjusted HR (aHR) for CUD on schizophrenia was slightly higher among males (aHR = 2.42, 95% CI 2.33-2.52) than females (aHR = 2.02, 95% CI 1.89-2.17); however, among 16-20-year-olds, the adjusted IRR (aIRR) for males was more than twice that for females (males: aIRR = 3.84, 95% CI 3.43-4.29; females: aIRR = 1.81, 95% CI 1.53-2.15). During 1972-2021, the annual average percentage change in PARFs for CUD in schizophrenia incidence was 4.8 among males (95% CI 4.3-5.3; p < 0.0001) and 3.2 among females (95% CI 2.5-3.8; p < 0.0001). In 2021, among males, PARF was 15%; among females, it was around 4%.

CONCLUSIONS

Young males might be particularly susceptible to the effects of cannabis on schizophrenia. At a population level, assuming causality, one-fifth of cases of schizophrenia among young males might be prevented by averting CUD. Results highlight the importance of early detection and treatment of CUD and policy decisions regarding cannabis use and access, particularly for 16-25-year-olds.

Measuring cannabis quantities in online surveys: A rapid review and proposals for ways forward

OBJECTIVES

Cannabis use quantities are relevant for determining cannabis-related harms. This research aims to provide an overview of the available methods to assess quantities through self-report.

METHODS

A rapid review of various strategies to collect information on cannabis use quantities through self-report. Two independent literature searches resulted in n = 38 studies included for review.

RESULTS

A total of n = 14 studies employed methods for collecting cannabis use quantities that are not suitable for online surveys (e.g., rolling a fake joint). Of the remaining n = 24 studies with items that are suitable for online surveys, the quantity assessment was performed in three different ways. The data collection was either carried out by asking (a) for the total number of joints (i.e., crude joint method), (b) for the total weight (i.e., crude weight method), or (c) for specific products separately, for example, for the amount of flower and resin (i.e., product-specific method). In only n = 8 studies, cannabis use quantities were ascertained by providing visual aids (e.g., illustration of various amounts of flower).

CONCLUSIONS

The crude joint method and the product-specific method are the two most promising methods to collect information on cannabis use quantities. Using visual aids may potentially improve the accuracy of those methods.

Changes in Quantity Measures of Various Forms of Cannabis Consumption among Emerging Adults in Canada in Relation to Policy and Public Health Developments

Limited research examines changes in quantities of various forms of smoked/vaped cannabis among regular consumers, including emerging adults (EAs; 18 to 29) in Canada. This information is particularly relevant in the current context of emerging cannabis behaviors among EAs related to political amendments (legalization of cannabis), vaping-related lung illnesses (EVALI), and unprecedented pandemics (COVID-19). This study investigated the impact of legalizing recreational cannabis use in Canada, the EVALI epidemic, and the COVID-19 pandemic on the quantity of smoked/vaped forms of cannabis in relation to gender differences. EAs retrospectively self-reported the quantity of herb, hash, concentrates, joint size, and the number of joints and vaping cartridges in relation to three consecutive developments: pre-legalization, post-legalization; pre-EVALI, post-EVALI, pre-COVID-19, and during COVID-19. The quantity of herb use significantly increased among heavy users, and vaping quantity significantly increased among light users. Overall, an increasing incremental trend was observed in the average quantity of cannabis forms used over time. Males consumed higher quantities of all cannabis forms than females. More males than females reported using concentrates (p < 0.05). These findings reveal unique aspects of the amount of various cannabis forms smoked/vaped in relation to gender and provides preliminary evidence of cannabis consumption behaviors in relation to changing social and cultural contexts.

Differentiating people who use cannabis heavily through latent class analysis

BACKGROUND

People who use cannabis daily or near-daily vary considerably in their daily dosage and use frequency, impacting both experienced effects and adverse consequences. This study identified heavy cannabis user groups according to consumption patterns and factors associated with class membership.

METHODS

We conducted a cross-sectional study of 380 Spanish residents (61.8% male; average age = 30.3 years) who had used cannabis ≥ 3 days/week throughout the past year. Participants were recruited through chain referral and cannabis social clubs. We applied latent class analysis (LCA) to cluster participants according to use intensity. LCA indicators included frequency of weekly cannabis use, joints smoked each day, cannabis dosage, and if cannabis was consumed throughout the day or only at specific times. Associations between class membership and socio-demographics, use patterns, motives, supply sources, adverse outcomes, and use of other substances were measured using ANOVA and chi-squared tests. Multinomial regression identified the factors associated with latent class membership.

RESULTS

Three latent classes (moderately heavy: 21.8%, heavy: 68.2%, very heavy: 10%) had average weekly cannabis intakes of 2.4, 5.5, and 18.3 g, respectively. Very heavy users were older ([Formula: see text]=17.77, p < 0.01), less educated [Formula: see text]=36.80, p < 0.001), and had used cannabis for longer (F = 4.62, p = 0.01). CAST scores (F = 26.51, p < 0.001) increased across the classes. The prevalence of past-month alcohol use was lower among the heaviest users ([Formula: see text]=5.95, p = 0.05). Cannabis was usually obtained from a club by very heavy users ([Formula: see text]=20.95, p < 0.001).

CONCLUSIONS

People who use cannabis heavily present three groups according to frequency and quantity of cannabis consumption. Use intensity is associated with increased cannabis-related problems. Differences among heavy users must be considered in harm reduction interventions in cannabis clubs and indicated prevention.

Legal sourcing of ten cannabis products in the Canadian cannabis market, 2019-2021: a repeat cross-sectional study

BACKGROUND

One of the objectives of cannabis legalization in Canada is to transition consumers from the illegal to the legal market. Little is known about how legal sourcing varies across different cannabis product types, provinces, and frequency of cannabis use.

METHODS

Data were analyzed from Canadian respondents in the International Cannabis Policy Study, a repeat cross-sectional survey conducted annually from 2019 to 2021. Respondents were 15,311 past 12-month cannabis consumers of legal age to purchase cannabis. Weighted logistic regression models estimated the association between legal sourcing ("all"/ "some"/ "none") of ten cannabis product types, province, and frequency of cannabis use over time.

RESULTS

The percentage of consumers who sourced "all" their cannabis products from legal sources in the past 12 months varied by product type, ranging from 49% of solid concentrate consumers to 82% of cannabis drink consumers in 2021. The percentage of consumers sourcing "all" their respective products legally was greater in 2021 than 2020 across all products. Legal sourcing varied by frequency of use: weekly or more frequent consumers were more likely to source "some" (versus "none") of their products legally versus less frequent consumers. Legal sourcing also varied by province, with a lower likelihood of legal sourcing in Québec of products whose legal sale was restricted (e.g., edibles).

CONCLUSION

Legal sourcing increased over time, demonstrating progress in the transition to the legal market for all products in the first three years of legalization in Canada. Legal sourcing was highest for drinks and oils and lowest for solid concentrates and hash.

Why Use Cannabis? Examining Motives for Cannabis Use in Individuals with Anxiety Disorders

This study examined cannabis use motives in individuals with anxiety disorders and compared motives between infrequent and frequent cannabis users. It was hypothesised that coping motives would be endorsed at a significantly higher rate than other motives, and that frequent cannabis users would endorse coping motives significantly more than infrequent users. Participants were 144 adults seeking clinical services for anxiety disorders who reported using cannabis. Cannabis use was categorized by infrequent (n = 54) and frequent (n = 90) use. Anxiety symptoms were assessed and deemed clinically significant. Participants completed measures of cannabis use motives, cannabis use patterns, and cannabis use disorder symptoms, cross-sectionally. Cannabis use motives were examined for the entire sample and compared between frequent and infrequent users. In general, cannabis users endorsed coping (i.e., use for managing distress) and enhancement (i.e., use for fun, pleasant feeling, or the high) motives at equal rates (p = .265) and more than other motives (p < .001). Frequent users reported using cannabis for coping and expansion motives (i.e., use to change one's thinking) significantly more than infrequent users. These results indicate that individuals with anxiety disorders use cannabis for various reasons, some of which may not be directly related to their mental health symptoms. Future research is needed to compare motives for cannabis use in those with anxiety disorders, other mental health populations, and the general population, as well as examine motives for cannabis use within specific anxiety disorders.

The Association between Recent Cannabis Use and Suicidal Ideation in Adults: A Population-based Analysis of the NHANES from 2005 to 2018

OBJECTIVE

With the increasing prevalence of cannabis use, there is a growing concern about its association with depression and suicidality. The aim of this study was to examine the relationship between recent cannabis use and suicidal ideation using a nationally representative data set.

METHODS

A cross-sectional analysis of adults was undertaken using National Health and Nutrition Examination Survey data from 2005 to 2018. Participants were dichotomized by whether or not they had used cannabis in the past 30 days. The primary outcome was suicidal ideation, and secondary outcomes were depression and having recently seen a mental health professional. Multiple logistic regression was used to adjust for potential confounders, and survey sample weights were considered in the model.

RESULTS

Compared to those with no recent use (n = 18,599), recent users (n = 3,127) were more likely to have experienced suicidal ideation in the past 2 weeks (adjusted odds ratio [aOR] 1.54, 95% CI, 1.19 to 2.00, P = 0.001), be depressed (aOR 1.53, 95% CI, 1.29 to 1.82, P < 0.001), and to have seen a mental health professional in the past 12 months (aOR 1.28, 95% CI, 1.04 to 1.59, P = 0.023).

CONCLUSIONS

Cannabis use in the past 30 days was associated with suicidal thinking and depression in adults. This relationship is likely multifactorial but highlights the need for specific guidelines and policies for the prescription of medical cannabis for psychiatric therapy. Future research should continue to characterize the health effects of cannabis use in the general population.

Cannabis flower prices and transitions to legal sources after legalization in Canada, 2019-2020

BACKGROUND

The post-tax price of legal cannabis has the potential to influence whether consumers transition from the illegal to legal cannabis market. The aims of the study were to: 1) estimate the percentage who report purchasing dried flower at different sources; 2) estimate the unit price of dried flower; and 3) examine the association between price and legality of purchase source.

METHODS

Repeat cross-sectional survey data come from Canadian respondents from the International Cannabis Policy Study conducted in 2019 and 2020. Respondents were recruited through online commercial panels, of legal age to purchase cannabis (up to 65 years), and purchased dried flower in the past 12-months (n = 4923). Weighted binary logistic regression models examined the association between price and legality of source.

RESULTS

The proportion of consumers last purchasing dried flower from legal sources increased from 2019 to 2020 (45.7% vs 58.1%) and in the past 12-months, the average percent of dried flower consumers reported purchasing from legal sources increased from 2019 to 2020 (55.7% vs 67.5%). The mean price of legal dried flower decreased in 2020 ($12.63 vs $11.16; p < 0.001), but remained more expensive than illegal dried flower in both years ($12.63 vs $9.04 in 2019; p < 0.001, $11.16 vs $9.41 in 2020; p < 0.001).

CONCLUSIONS

Two years after legalization in Canada, the price of dried flower from legal sources decreased, along with a greater percentage of consumers purchasing from legal sources than after one year. Price and retail policies must continue to encourage the transition to the legal market in Canada.

Lower-Risk Cannabis Use Guidelines (LRCUG) for reducing health harms from non-medical cannabis use: A comprehensive evidence and recommendations update

BACKGROUND

Cannabis use is common, especially among young people, and is associated with risks for various health harms. Some jurisdictions have recently moved to legalization/regulation pursuing public health goals. Evidence-based 'Lower Risk Cannabis Use Guidelines' (LRCUG) and recommendations were previously developed to reduce modifiable risk factors of cannabis-related adverse health outcomes; related evidence has evolved substantially since. We aimed to review new scientific evidence and to develop comprehensively up-to-date LRCUG, including their recommendations, on this evidence basis.

METHODS

Targeted searches for literature (since 2016) on main risk factors for cannabis-related adverse health outcomes modifiable by the user-individual were conducted. Topical areas were informed by previous LRCUG content and expanded upon current evidence. Searches preferentially focused on systematic reviews, supplemented by key individual studies. The review results were evidence-graded, topically organized and narratively summarized; recommendations were developed through an iterative scientific expert consensus development process.

RESULTS

A substantial body of modifiable risk factors for cannabis use-related health harms were identified with varying evidence quality. Twelve substantive recommendation clusters and three precautionary statements were developed. In general, current evidence suggests that individuals can substantially reduce their risk for adverse health outcomes if they delay the onset of cannabis use until after adolescence, avoid the use of high-potency (THC) cannabis products and high-frequency/-intensity of use, and refrain from smoking-routes for administration. While young people are particularly vulnerable to cannabis-related harms, other sub-groups (e.g., pregnant women, drivers, older adults, those with co-morbidities) are advised to exercise particular caution with use-related risks. Legal/regulated cannabis products should be used where possible.

CONCLUSIONS

Cannabis use can result in adverse health outcomes, mostly among sub-groups with higher-risk use. Reducing the risk factors identified can help to reduce health harms from use. The LRCUG offer one targeted intervention component within a comprehensive public health approach for cannabis use. They require effective audience-tailoring and dissemination, regular updating as new evidence become available, and should be evaluated for their impact.

Recent cannabis use and nightly sleep duration in adults: a population analysis of the NHANES from 2005 to 2018

BACKGROUND

While popularly consumed for its perceived benefits as a sleeping aid, the impact of cannabis on sleep-wake regulation in clinical studies is inconclusive. The purpose of this study was to determine the relationship between cannabis use and nightly sleep duration in a nationally representative dataset.

METHODS

A cross-sectional analysis of adults was undertaken using the National Health and Nutrition Examination Survey data from 2005 to 2018. Respondents were dichotomized as recent users or non-users if they had used or not used cannabis in the past 30 days, respectively. The primary outcome was nightly sleep duration, categorized as short (<6 hours), optimal (6-9 hours), and long (>9 hours). Multinomial logistic regression was used to adjust for sociodemographic and health-related covariates, and survey sample weights were used in modeling.

RESULTS

From a sample representing approximately 146 million adults in the USA, 14.5% reported recent cannabis use. In an adjusted analysis, recent users were more likely than non-users to report both short sleep (OR 1.34, 95% CI 1.12 to 1.59, p<0.001) and long sleep (OR 1.56, 95% CI 1.25 to 1.96, p<0.001). Heavy users (≥20 of the past 30 days) were even more likely to be at the extremes of nightly sleep duration.

DISCUSSION

Recent cannabis use was associated with the extremes of nightly sleep duration in a nationally representative sample of adults, with suggestions of a dose-response relationship. Our findings highlight the need to further characterize the sleep health of regular cannabis users in the population.

Cannabis Growers in the United States: Findings From a National Household Survey 2010−2014

Given the rapidly changing U.S. cannabis legislation landscape, the aim of this article is to describe individuals who self-reported growing cannabis in the past year by selected characteristics and geographical location. Using data from 2010 to 2014 National Survey on Drug Use and Health, we conducted bivariate chi-square tests and ran a multivariable logistic regression model to examine the indicators associated with growing cannabis. Approximately, 484,000 individuals aged 12+ self-reported growing cannabis in the past year (1.6% of marijuana users). Predictors of growing cannabis included being male and self-reported reporting using cannabis for a greater number of days. Data showed differences in the proportion of cannabis growers by the state of residence. Obtaining a baseline estimate of cannabis growing practices prior to recreational cannabis markets emerging (2014) is important because such practices may undermine efforts to discourage diversion to youth. Tracking these acquisition patterns will better inform content for public health messaging and prevention education, particularly those targeting youth.

Self-isolation: A significant contributor to cannabis use during the COVID-19 pandemic

BACKGROUND

Emerging research suggests the COVID-19 pandemic has resulted in a significant increase in self-reported isolation and loneliness in a large proportion of the population. This is particularly concerning given that isolation and loneliness are associated with increased cannabis use, as well as using cannabis to cope with negative affect. Objective: We investigated whether self-isolation due to COVID-19 and using cannabis to cope with depression were unique and/or interactive predictors of cannabis use during the pandemic, after controlling for pre-pandemic levels of cannabis use. Method: A sample of 70 emerging adults (mean age = 23.03; 34.3% male) who used both alcohol and cannabis pre-pandemic completed measures of cannabis use (i.e., quantity x frequency) and a novel COVID-19 questionnaire between March 23 and June 15, 2020. Pre-pandemic cannabis use levels had been collected four months earlier. Results: Linear regressions indicated self-isolation and coping with depression motives for cannabis use during the pandemic were significant predictors of pandemic cannabis use levels after accounting for pre-pandemic use levels. There was no interaction between coping with depression motives and self-isolation on cannabis use during the pandemic. Conclusions: Those who engaged in self-isolation were found to use 20% more cannabis during the pandemic than those who did not. Our results suggest that self-isolation is a unique risk factor for escalating cannabis use levels during the pandemic. Thus, self-isolation may inadvertently lead to adverse public health consequences in the form of increased cannabis use.