A Description of the Medical Cannabis Use in Ontario, Canada

Risk of depressive disorders associated with medical cannabis authorization: A propensity score matched cohort study

There is an increase in the medical use of cannabis. However, the safety of medical cannabis, particularly for mental health conditions, has not yet been clearly established. Thus, this study assessed the risk of emergency department (ED) visits and hospitalization for depressive disorders among medical cannabis users. We conducted a retrospective longitudinal cohort study of patients who received medical authorization to use cannabis from 2014 to 2019 in Ontario, matched (1:3 ratio) to population-based controls using propensity scores. Conditional Cox regressions were used to assess the association between cannabis authorization and the outcome. A total of 54,006 cannabis-authorized patients and 161,265 controls were analyzed. Approximately 39% were aged under 50 years, 54% were female, and 16% had a history of anxiety or mood disorders. The adjusted hazard ratio (aHR) for depressive disorders was 2.02 (95%CI: 1.83-2.22). The aHR was 2.23 (1.95-2.55) among subjects without prior mental health disorders. The interaction between sex (or age) and exposure was not significant. In conclusion, medical cannabis authorization was associated with an increased risk of depressive disorders. This finding highlights the need for a careful risk-benefit assessment when authorizing cannabis, particularly for patients who seek cannabis to treat a depressive condition.

Cannabis Seeds Authentication by Chloroplast and Nuclear DNA Analysis Coupled with High-Resolution Melting Method for Quality Control Purposes

Background: Cannabis plants and their seed have been used in many cultures as a source of medicine and feeding during history. Today, there is an increasing demand for cannabis seeds for medical use. Moreover, a seed sales market with no legal regulations has also grown. This may pose some issues if a quality control is not set in place. Identification of cannabis strains is important for quality control purposes in a nonregulated growing market and in cases of illegal traffic and medical use. Owing to the high price as a pharmacological drug, commercial products of cannabis plants and seeds for medical users are often subjected to adulterations, either when packing or distributing certified seeds in the market. Materials and Methods: Cannabis commercial seeds and cannabis seeds for medical use were analyzed with high-resolution melting (HRM) analysis using barcoding markers. Humulus lupulus L. plants from a local market were used as outgroup control. DNA barcoding uses specific regions of the genome to identify differences in the genetic sequence of conserved regions such as internal transcribed spacer (ITS) and rbcL. DNA barcoding data can be generated with real-time polymerase chain reaction combined with HRM analysis to distinguish specific conserved DNA regions of closely related species. HRM analysis is the method of choice for rapid analysis of sequence variation. Results: The melting temperature (Tm) of homogeneous packages was consistent with single genotypes. However, packages containing contaminating seeds showed Tm differences of 0.2°C on average. Conclusions: An effective, rapid, and low-cost method based on ITS nuclear DNA and on chloroplast rbcL regions for screening and detection of contamination in commercial cannabis seeds was developed and applied for the analysis of different samples. This approach can be used as a quality control tool for cannabis seeds or other plant material.

Substance Use Disorders and Psychoactive Drug Poisoning in Medically Authorized Cannabis Patients: Longitudinal Cohort Study

OBJECTIVES

Poisoning from psychoactive drugs and substance use disorders (SUD) have been reported among non-medical cannabis users. However, little is known about medical cannabis users and their risk for poisoning and/or development of SUD. This study assessed the risk of emergency department (ED) visits or hospitalization for 1) poisoning by psychoactive drugs and 2) mental/behavioural disorders due to the use of psychoactive drugs and other substances, in medically authorized cannabis patients in Ontario, Canada from 2014-2017.

METHODS

A cohort study of adult patients authorized for medical cannabis that were matched to population-based controls. ED visit/hospitalization were assessed with a main diagnostic code for: 1) poisoning by psychoactive drugs; 2) mental and behavioural disorder due to psychoactive drugs or other substance use. Conditional Cox proportional hazards regressions were conducted.

RESULTS

18,653 cannabis patients were matched to 51,243 controls. During a median follow-up of 243 days, the incidence rate for poisoning was 4.71 per 1,000 person-years (95%CI: 3.71-5.99) for cases and 1.73 per 1,000 person-years (95% CI: 1.36-2.19) for controls. The adjusted hazard ratio (aHR) was 2.45 (95%CI: 1.56-3.84). For mental/behavioural disorders, the incident rates were 8.89 (95% CI: 7.47-10.57) and 5.01 (95% CI: 4.36-5.76) in the cannabis and the controls group. The aHR was 2.27 (95%CI: 1.66-3.11). No difference was observed between males and females (P-value for interaction > 0.05).

CONCLUSIONS

Our study observed a short-term increased risk of ED visit/hospitalization for poisoning or for mental/behavioural disorders (from use of psychoactive drugs and other substances)- in medically authorized cannabis patients.

Medical cannabis use in Canada and its impact on anxiety and depression: A retrospective study

This was a retrospective study of patients utilizing medical cannabis who received their medical cannabis documentation and allotment from a Harvest Medicine clinic in Canada to determine the impact of medical cannabis on anxiety and depression outcomes. Patients included in the study were at least 18 years of age with completed validated questionnaires for anxiety (GAD-7) and depression (PHQ-9) at their initial evaluation and at least one follow-up visit. There were 7,362 patients included in the sample, of which the average age was 49.8 years, and 53.1% were female. There were statistically significant improvements between baseline and follow-up scores for both the GAD-7 and PHQ-9, with larger improvements seen for patients who were actively seeking medical cannabis to treat anxiety or depression. From 12 months on, those reporting anxiety had an average decrease in GAD-7 scores that was greater than the minimum clinically important difference of 4, and the same was seen for patients reporting depression from 18 months on, with the average decrease in PHQ-9 scores more than the MCID minimum clinically important difference of 5. This study provides some evidence to support the effectiveness of medical cannabis as a treatment for anxiety and depression.

Exploring cannabis use and perspectives among psoriatic disease patients

OBJECTIVE

To assess the correlation between cannabis use and psoriatic disease severity, health-related quality of life, pain, psychosocial outcomes, and cytokine levels in psoriasis (PsC) and psoriatic arthritis (PsA) patients.

METHODS

PsC and PsA patients enrolled in the International Psoriasis and Arthritis Research Team (IPART) program were surveyed on cannabis use and were asked to provide a serum and urine sample. Demographic and clinical variables were compared between users and non-users using Student's t-test or Mann-Whitney U test for continuous variables, and chi-square or Fisher's exact test for categorical variables.

RESULTS

Of 151 respondents, 30% reported current cannabis use within the last year. Compared to non-users, cannabis users were younger and had a shorter PsA duration and poorer mental health as measured by the SF-36. Other measures of health-related quality of life and pain were comparable between the groups. Respondents' primary perceived benefits of cannabis use were aid in sleep and arthritis pain relief, but there was no difference in pain between users and non-users. No THC was detected in the urine of non-users while users had a mean level of 19.6 ng/ml. Serum IL-23 levels were statistically significantly higher in non-users than in users.

CONCLUSION

A third of the patients used cannabis within the past year, and 54.3% of users reported the use of cannabis for arthritis pain relief. However, there was no difference in pain scores. Comprehensive education for providers on the current body of evidence and further studies on cannabis use and outcomes in psoriatic disease are needed. Key Points • A third of patients with psoriatic arthritis have used cannabis in the past year. • Most used it for better sleep and control of pain. • There was no difference in pain scores between users and non-users. • IL-23 levels were significantly higher in non-users.

Legal status of recreational cannabis and self-reported substitution of cannabis for opioids or prescription pain medication in Canada and the United States

Aims: With increased liberalization of cannabis policies in North America, there is growing interest in the use of cannabis to manage pain instead of opioids. The objectives of the study were to (1) examine the use of cannabis for pain relief in Canada and the United States (US) in 2018 and 2019; (2) examine the association between recreational cannabis laws and changes in the use of cannabis for pain relief, instead of opioids or prescription pain medication. Methods: Repeat cross-sectional survey data were used from Wave 1 and Wave 2 of the International Cannabis Policy Study conducted in 2018 and 2019 in Canada and the US. Respondents were recruited through commercial panels, aged 16-65, and had ever tried cannabis (N = 44,119). Weighted binary logistic regression models examined the association between the legal status of recreational cannabis and cannabis use for pain relief instead of opioids or prescription pain medication (n = 15,092). Results: Between 14-33% of cannabis consumers in Canada and the US reported using cannabis to manage headaches or pain. Of these consumers, 79% and 78% respondents in Canada; 80% and 83% in US illegal states; and 83% and 84% in US legal states, in 2018 and 2019, respectively, reported cannabis use for pain relief instead of opioids or prescription pain medication. There was little evidence of an association between the legal status of recreational cannabis and cannabis use for pain relief instead of opioids or prescription pain medication, among Canadian (AOR = 0.98, 95% CI: 0.78, 1.22) and US respondents (AOR = 1.11, 95% CI: 0.96, 1.28). Conclusions: Although substitution of cannabis for opioids or prescription pain medication is common among those who use cannabis for pain, there does not seem to be a significant difference according to cannabis legality. Future research should examine cannabis and opioid substitution using different research designs and time frames.

Incidence and Predictors of Cannabis-Related Poisoning and Mental and Behavioral Disorders among Patients with Medical Cannabis Authorization: A Cohort Study

OBJECTIVE

As medical cannabis use increases in North America, establishing its safety profile is a priority. The objective of this study was to assess rates of emergency department (ED) visits and hospitalizations due to poisoning by cannabis, and cannabis-related mental health disorders among medically authorized cannabis patients in Ontario, Canada, between 2014 and 2017.

METHODS

This is a retrospective cohort study of patients who received medical cannabis authorization in Ontario, Canada, using data collected in participating cannabis clinics. Outcomes included ED visit/hospitalization with a main diagnosis code for: cannabis/cannabinoid poisoning; and mental/behavioral disorders due to cannabis use. Cox proportional hazard regressions were utilized to analyze the data.

RESULTS

From 29,153 patients who received medical authorization, 23,091 satisfied the inclusion criteria. During a median follow-up of 240 days, 14 patients visited the ED or were hospitalized for cannabis poisoning-with an incidence rate of 8.06 per 10,000 person-years (95% CI: 4.8-13.6). A total of 26 patients visited the ED or were hospitalized for mental and behavioral disorders due to cannabis use-with an incidence rate of 15.0 per 10,000 person-years (95% CI: 10.2-22.0). Predictors of cannabis-related mental and behavioral disorders include prior substance use disorders, other mental disorders, age, diabetes, and chronic obstructive pulmonary disease.

CONCLUSIONS

The results suggest that the incidence of cannabis poisoning or cannabis-related mental and behavioral disorders was low among patients who were authorized to use cannabis for medical care. Identified predictors can help to target patients with potential risk of the studied outcomes.

Medical cannabis authorization and the risk of cardiovascular events: a longitudinal cohort study

Background

Cannabis is increasingly used for therapeutic purpose. However, its safety profile is not well known. This study assessed the risk of cardiovascular-related emergency department (ED) visit and hospitalization in adult patients authorized to use medical cannabis in Ontario, Canada from 2014 to 2017.

Methods

This is a longitudinal cohort study of patients who received medical cannabis authorization and followed-up in cannabis clinics, matched to population-based controls. The primary outcome was an ED visit or hospitalization for acute coronary syndrome (ACS) or stroke; and secondary outcome was for any cardiovascular event. Conditional Cox proportional hazards regression was used to assess the association between cannabis authorization and risk.

Results

18,653 cannabis patients were matched to 51,243 controls. During a median follow-up of 242 days, the incidence rates for ACS or stroke were 7.19/1000 person-years and 5.67/1000 person-years in the cannabis and controls group, respectively- adjusted hazard ratio (aHR) of 1.44 (95% CI 1.08–1.93). When stratified by sex, the association was only statistically significant among males: aHR 1.77 (1.23–2.56). For the secondary outcome (any CV events), the aHR was 1.47 (1.26–1.72). The aHR among males and females were 1.52 (1.24–1.86) and 1.41 (1.11–1.79), respectively. Tested interaction between cannabis authorization and sex was not significant (p > 0.05).

Conclusions

Medical cannabis authorization was associated with an increased risk of ED visits or hospitalization for CV events including stroke and ACS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02229-6.

Comparing medical cannabis use in 5 US states: a retrospective database study

Background

US states have been adopting their own medical cannabis laws since 1996. There is substantial variability in the medical cannabis programs between states, and these differences have not been thoroughly investigated in the literature. The objective of the study was to compare medical cannabis patient characteristics across five states to identify differences potentially caused by differing policies surrounding condition eligibility.

Methods

We conducted secondary analyses following a retrospective study of a registry database with data from 33 medical cannabis evaluation clinics in the US, owned and operated by CB2 Insights. This study narrowed the dataset to include patients from five states with the largest samples: Massachusetts (n = 27,892), Colorado (n = 16,434), Maine (n = 4591), Connecticut (n = 2643), and Maryland (n = 2403) to conduct an in-depth study of the characteristics of patients accessing medical cannabis in these states, including analysis of variance to compare average ages and number of conditions and chi-squared tests to compare proportions of patient characteristics between states.

Results

Average ages varied between the states, with the youngest average in Connecticut (42.2) and the oldest in Massachusetts (47.0). Males represented approximately 60% of the patients with data on gender in each state. The majority of patients in each state had cannabis experience prior to seeking medical certification. Primary medical conditions varied for each state, with chronic pain, anxiety, and back and neck problems topping the list in varying orders for Massachusetts, Maine, and Maryland. Colorado had 78.7% of patients report chronic pain as their primary condition, and 70.4% of patients in Connecticut reported post-traumatic stress disorder as their primary medical condition.

Conclusion

This study demonstrated the significant impact that policy has on patients’ access to medical cannabis in Massachusetts, Colorado, Maine, Connecticut, and Maryland utilizing real-world data. It highlights how qualifications differ between the five states and brings into question the routes through which patients in states with stricter regulations surrounding eligible conditions choose to seek treatment with cannabis. These patients may turn to alternative treatments, or to the illicit or recreational cannabis markets, where permitted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-021-00075-z.

Evaluation of Patient Reported Safety and Efficacy of Cannabis From a Survey of Medical Cannabis Patients in Canada

With the medical use of cannabis permitted in Canada since 2001, patients seek to use this botanical drug to treat a range of medical conditions. However, many healthcare practitioners express the need for further scientific evidence around the use of medical cannabis. This real-world evidence study aimed to address the paucity of scientific data by surveying newly registered medical cannabis patients, before beginning medical cannabis treatment, and at one follow up 6 weeks after beginning medical cannabis treatment. The goal was to collect data on efficacy, safety and cannabis product type information to capture the potential impact medical cannabis had on patient-reported quality of life (QOL) and several medical conditions over a 6-week period using validated questionnaires. The 214 participants were mainly male (58%) and 57% of the population was older than 50. The most frequently reported medical conditions were recurrent pain, post-traumatic stress disorder (PTSD), anxiety, sleep disorders [including restless leg syndrome (RLS)], and arthritis and other rheumatic disorders. Here we report that over 60% of our medical cannabis cohort self-reported improvements in their medical conditions. With the use of validated surveys, we found significant improvements in recurrent pain, PTSD, and sleep disorders after 6 weeks of medical cannabis treatment. Our findings from patients who reported arthritis and other rheumatic disorders are complex, showing improvements in pain and global activity sub-scores, but not overall changes in validated survey scores. We also report that patients who stated anxiety as their main medical condition did not experience significant changes in their anxiety after 6 weeks of cannabis treatment, though there were QOL improvements. While these results show that patients find cannabis treatment effective for a broad range of medical conditions, cannabis was not a remedy for all the conditions investigated. Thus, there is a need for future clinical research to support the findings we have reported. Additionally, while real-world evidence has not historically been utilized by regulatory bodies, we suggest changes in public policy surrounding cannabis should occur to reflect patient reported efficacy of cannabis from real-world studies due to the uniqueness of medical cannabis's path to legalization.

Medical cannabis use in the United States: a retrospective database study

Introduction

Growing interest in the medicinal properties of cannabis has led to an increase in its use to treat medical conditions, and the establishment of state-specific medical cannabis programs. Despite medical cannabis being legal in 33 states and the District of Colombia, there remains a paucity of data characterizing the patients accessing medical cannabis programs.

Methods

We retrospectively reviewed a registry with data from 33 medical cannabis evaluation clinics in the United States, owned and operated by CB2 Insights. Data were collected primarily by face-to-face interviews for patients seeking medical cannabis certification between November 18, 2018 and March 18, 2020. Patients were removed from the analysis if they did not have a valid date of birth, were less than 18, or did not have a primary medical condition reported; a total of 61,379 patients were included in the analysis. Data were summarized using descriptive statistics expressed as a mean (standard deviation (SD)) or median (interquartile range (IQR)) as appropriate for continuous variables, and number (percent) for categorical variables. Statistical tests performed across groups included t-tests, chi-squared tests and regression.

Results

The average age of patients was 45.5, 54.8% were male and the majority were Caucasian (87.5%). Female patients were significantly older than males (47.0 compared to 44.6). Most patients reported cannabis experience prior to seeking medical certification (66.9%). The top three mutually exclusive primary medical conditions reported were unspecified chronic pain (38.8%), anxiety (13.5%) and post-traumatic stress disorder (PTSD) (8.4%). The average number of comorbid conditions reported was 2.7, of which anxiety was the most common (28.3%). Females reported significantly more comorbid conditions than males (3.1 compared to 2.3).

Conclusion

This retrospective study highlighted the range and number of conditions for which patients in the US seek medical cannabis. Rigorous clinical trials investigating the use of medical cannabis to treat pain conditions, anxiety, insomnia, depression and PTSD would benefit a large number of patients, many of whom use medical cannabis to treat multiple conditions.